The tryptophan metabolite, kynurenic acid (KYNA), is a preferential antagonist of the α7 nicotinic acetylcholine receptor at endogenous brain concentrations. Recent studies have suggested that increase of brain KYNA levels is involved in psychiatric disorders such as schizophrenia and depression. KYNA-producing enzymes have broad substrate specificity for aminoacids, and brain uptake of kynurenine (KYN), the immediate precursor of KYNA, is via large neutral aminoacid transporters (LAT). In the present study, to find out aminoacids with the potential to suppress KYNA production, we comprehensively investigated the effects of proteinogenic aminoacids on KYNA formation and KYN uptake in rat brain in vitro. Cortical slices of rat brain were incubated for 2 h in Krebs-Ringer buffer containing a physiological concentration of KYN with individual aminoacids. Ten out of 19 aminoacids (specifically, leucine, isoleucine, phenylalanine, methionine, tyrosine, alanine, cysteine, glutamine, glutamate, and aspartate) significantly reduced KYNA formation at 1 mmol/L. These aminoacids showed inhibitory effects in a dose-dependent manner, and partially inhibited KYNA production at physiological concentrations. Leucine, isoleucine, methionine, phenylalanine, and tyrosine, all LAT substrates, also reduced tissue KYN concentrations in a dose-dependent manner, with their inhibitory rates for KYN uptake significantly correlated with KYNA formation. These results suggest that five LAT substrates inhibit KYNA formation via blockade of KYN transport, while the other aminoacids act via blockade of the KYNA synthesis reaction in brain. Aminoacids can be a good tool to modulate brain function by manipulation of KYNA formation in the brain. This approach may be useful in the treatment and prevention of neurological and psychiatric diseases associated with increased KYNA levels.

... this page: //medlineplus.gov/ency/article/002222.htm Aminoacids To use the sharing features on this page, please enable JavaScript. Aminoacids are organic compounds that combine to form proteins . ...

To define the adaptations that conserve aminoacids and muscle protein when dietary protein intake is inadequate, rats (60-70 g final wt) were fed a normal or protein-deficient (PD) diet (18 or 1% lactalbumin), and their muscles were studied in vitro. After 7 days on the PD diet, both protein degradation and synthesis fell 30-40% in skeletal muscles and atria. This fall in proteolysis did not result from reduced aminoacid supply to the muscle and preceded any clear decrease in plasma aminoacids. Oxidation of branched-chain aminoacids, glutamine and alanine synthesis, and uptake of alpha-aminoisobutyrate also fell by 30-50% in muscles and adipose tissue of PD rats. After 1 day on the PD diet, muscle protein synthesis and aminoacid uptake decreased by 25-40%, and after 3 days proteolysis and leucine oxidation fell 30-45%. Upon refeeding with the normal diet, protein synthesis also rose more rapidly (+30% by 1 day) than proteolysis, which increased significantly after 3 days (+60%). These different time courses suggest distinct endocrine signals for these responses. The high rate of protein synthesis and low rate of proteolysis during the first 3 days of refeeding a normal diet to PD rats contributes to the rapid weight gain ("catch-up growth") of such animals.

... this process. One group of these disorders is aminoacid metabolism disorders. They include phenylketonuria (PKU) and maple syrup urine disease. Aminoacids are "building blocks" that join together to form ...

There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral aminoacids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral aminoacid therapy, explains how parenteral aminoacid solutions are formulated, and compares the advantages and disadvantages of different parenteral aminoacid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness. PMID:28287411

There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral aminoacids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral aminoacid therapy, explains how parenteral aminoacid solutions are formulated, and compares the advantages and disadvantages of different parenteral aminoacid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness.

Full Text Available The chronological lifespan of Saccharomyces cerevisiae represents the duration of cell survival in the postdiauxic and stationary phases. Using a prototrophic strain derived from the standard auxotrophic laboratory strain BY4742, we showed that supplementation of non-essential aminoacids to a synthetic defined (SD medium increases maximal cell growth and extends the chronological lifespan. The positive effects of aminoacids can be reproduced by modulating the medium pH, indicating that aminoacids contribute to chronological longevity in a cell-extrinsic manner by alleviating medium acidification. In addition, we showed that the aminoacid-mediated effects on extension of chronological longevity are independent of those achieved through a reduction in the TORC1 pathway, which is mediated in a cell-intrinsic manner. Since previous studies showed that extracellular acidification causes mitochondrial dysfunction and leads to cell death, our results provide a path to premature chronological aging caused by differences in available nitrogen sources. Moreover, acidification of culture medium is generally associated with culture duration and cell density; thus, further studies are required on cell physiology of auxotrophic yeast strains during the stationary phase because an insufficient supply of essential aminoacids may cause alterations in environmental conditions.

C-hordein. The production of the S-rich B/gamma- and D-hordeins was increased and significantly higher steady-state expression levels of the corresponding genes were observed. The increased synthesis of S-rich hordeins appeared to increase the demand for sulphur and the S-rich aminoacids (cysteine......Antisense- or RNAi-mediated suppression of the biosynthesis of nutritionally inferior storage proteins is a promising strategy for improving the aminoacid profile of seeds. However, the potential pleiotropic effects of this on interconnected pathways and the agronomic quality traits need...... to be addressed. In the current study, a transcriptomic analysis of an antisense C-hordein line of barley was performed, using a grain-specific cDNA array. The C-hordein antisense line is characterized by marked changes in storage protein and aminoacid profiles, while the seed weight is within the normal range...

Learning the 20 standard aminoacids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving aminoacids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

The potential of the time-dependent aminoacid racemisation reaction as a method of age assessment was first reported by Hare and Abelson (1968). They noted that in specimens of the bivalve mollusc Mercenaria sp., greater concentrations of aminoacids in the D-configuration with increasing fossil age. Hare and Abelson (1968) also reported negligible racemisation in a modern specimen of Mecanaria sp. On this basis they suggested that the extent of aminoacid racemisation (epimerisation in the case of isoleucine) may be used to assess the age of materials within and beyond the range of radiocarbon dating. For the past thirty years aminoacid racemisation has been extensively applied in Quaternary research as a method of relative and numeric dating, and a particularly large literature has emerged on the subject 12 refs.

Aminoacids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of aminoacids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral aminoacids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the aminoacids in carbonaceous chondritcs and their relevance to the origin of life.

A set of ten azetidinic aminoacids, that can be envisioned as C-4 alkyl substituted analogues of trans-2-carboxyazetidine-3-acetic acid (t-CAA) and/or conformationally constrained analogues of (R)- or (S)-glutamic acid (Glu) have been synthesized in a diastereo- and enantiomerically pure form from...... of two diastereoisomers that were easily separated and converted in two steps into azetidinic aminoacids. Azetidines 35-44 were characterized in binding studies on native ionotropic Glu receptors and in functional assays at cloned metabotropic receptors mGluR1, 2 and 4, representing group I, II and III...... beta-amino alcohols through a straightforward five step sequence. The key step of this synthesis is an original anionic 4-exo-tet ring closure that forms the azetidine ring upon an intramolecular Michael addition. This reaction was proven to be reversible and to lead to a thermodynamic distribution...

Full Text Available Differentiation of cancer stem cells (CSCs into cancer cells causes increased sensitivity to chemotherapeutic agents. Although inhibition of mammalian target of rapamycin (mTOR leads to CSC survival, the effect of branched chain aminoacids (BCAAs, an mTOR complex 1 (mTORC1 activator remains unknown. In this study, we examined the effects of BCAA on hepatocellular carcinoma (HCC cells expressing a hepatic CSC marker, EpCAM. We examined the effects of BCAA and/or 5-fluorouracil (FU on expression of EpCAM and other CSC-related markers, as well as cell proliferation in HCC cells and in a xenograft mouse model. We also characterized CSC-related and mTOR signal-related molecule expression and tumorigenicity in HCC cells with knockdown of Rictor or Raptor, or overexpression of constitutively active rheb (caRheb. mTOR signal-related molecule expression was also examined in BCAA-treated HCC cells. In-vitro BCAA reduced the frequency of EpCAM-positive cells and improved sensitivity to the anti-proliferative effect of 5-FU. Combined 5-FU and BCAA provided better antitumor efficacy than 5-FU alone in the xenograft model. Stimulation with high doses of BCAA activated mTORC1. Knockdown and overexpression experiments revealed that inhibition of mTOR complex 2 (mTORC2 or activation of mTORC1 led to decreased EpCAM expression and little or no tumorigenicity. BCAA may enhance the sensitivity to chemotherapy by reducing the population of cscs via the mTOR pathway. This result suggests the utility of BCAA in liver cancer therapy.

acid degradation. Since secondary metabolism occurs after active growth has ceased, this growth stimulation resulted in suppression of expression of aflatoxin biosynthesis genes. On the other hand, increased activities in degradation pathways for branched-chain aminoacids probably are required for the activation of the aflatoxin pathway by providing building blocks and energy regeneration. Metabolic flux in primary metabolism apparently has an important role in the expression of genes of secondary metabolism.

branched-chain aminoacid degradation. Since secondary metabolism occurs after active growth has ceased, this growth stimulation resulted in suppression of expression of aflatoxin biosynthesis genes. On the other hand, increased activities in degradation pathways for branched-chain aminoacids probably are required for the activation of the aflatoxin pathway by providing building blocks and energy regeneration. Metabolic flux in primary metabolism apparently has an important role in the expression of genes of secondary metabolism.

Aminoacids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 aminoacids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides aminoacid biosynthesis, which has already been investigated in great detail, the catabolism of aminoacids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of aminoacids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of aminoacid catabolism and summarize current knowledge on aminoacid degradation pathways and their regulation in the context of plant cell physiology.

Full Text Available Aminoacids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of aminoacid reactivities suggest that aminoacids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess aminoacid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of aminoacid compounds in the global atmosphere, we determined free aminoacids (FAAs in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS to analyze 20 aminoacids and quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total aminoacid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher aminoacid concentrations were present in the ultrafine aerosol fraction (< 0.49 μm and accounted for the majority of the total aminoacid content. Local marine sources dominate the boreal summer aminoacid concentrations, with the exception of the regional input from Icelandic volcanic emissions.

Full Text Available Aminoacids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of aminoacid reactivities suggest that aminoacids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess aminoacid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of aminoacid compounds in the global atmosphere, we determined free aminoacids (FAAs in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS to analyze 20 aminoacids to quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total aminoacid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher aminoacid concentrations were present in the ultrafine aerosol fraction (<0.49 μm and accounted for the majority of the total aminoacid content. Local marine sources dominate the boreal summer aminoacid concentrations, with the exception of the regional input from Icelandic volcanics.

Dairy cow protein and aminoacid nutrition have a significant role in sustainable dairying. Protein, aminoacids, and nitrogen are inextricably linked through effects in the rumen, metabolism of the cow, and environmental nutrient management. Feeding systems have been making progress toward emphasiz...

intake, bodyweight gain, egg weight or efficiency of lysine utilisation, but ... When modelling the aminoacid requirements of broiler breeder ... Two hundred and forty Cobb broiler breeder hens aged 27 weeks were housed in individual cages. ..... feeds with synthetic aminoacids is of importance not only on nutritional and.

Meteorites may have contributed aminoacids to the prebiotic Earth, affecting the global ratio of right-handed to left-handed (D/L) molecules. We calculate D/L ratios for seven biological, α-hydrogen, protein aminoacids over a variety of plausible parent body thermal histories, based on meteorite evidence and asteroid modeling. We show that aminoacids in meteorites do not necessarily undergo complete racemization by the time they are recovered on Earth. If the mechanism of aminoacid formation imposes some enantiomeric preference on the aminoacids, a chiral signature can be retained through the entire history of the meteorite. Original enantiomeric excesses in meteorites such as Murchison, which have undergone apparently short and cool alteration scenarios, should have persisted to the present time. Of the seven aminoacids for which relevant data are available, we expect glutamic acid, isoleucine, and valine, respectively, to be the most likely to retain an initial enantiomeric excess, and phenylalanine, aspartic acid, and alanine the least. Were the D/L ratio initially identical in each aminoacid, final D/L ratios could be used to constrain the initial ratio and the thermal history experienced by the whole suite.

A deficiency of dietary protein or aminoacids has long been known to impair immune function and increase the susceptibility of animals and humans to infectious disease. However, only in the past 15 years have the underlying cellular and molecular mechanisms begun to unfold. Protein malnutrition reduces concentrations of most aminoacids in plasma. Findings from recent studies indicate an important role for aminoacids in immune responses by regulating: (1) the activation of T lymphocytes, B lymphocytes, natural killer cells and macrophages; (2) cellular redox state, gene expression and lymphocyte proliferation; and (3) the production of antibodies, cytokines and other cytotoxic substances. Increasing evidence shows that dietary supplementation of specific aminoacids to animals and humans with malnutrition and infectious disease enhances the immune status, thereby reducing morbidity and mortality. Arginine, glutamine and cysteine precursors are the best prototypes. Because of a negative impact of imbalance and antagonism among aminoacids on nutrient intake and utilisation, care should be exercised in developing effective strategies of enteral or parenteral provision for maximum health benefits. Such measures should be based on knowledge about the biochemistry and physiology of aminoacids, their roles in immune responses, nutritional and pathological states of individuals and expected treatment outcomes. New knowledge about the metabolism of aminoacids in leucocytes is critical for the development of effective means to prevent and treat immunodeficient diseases. These nutrients hold great promise in improving health and preventing infectious diseases in animals and humans.

NASA's Stardust spacecraft returned samples from comet 81P/Wild 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and aminoacids, but the origin of these compounds (cometary- vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these aminoacids to determine their origin, leading to the first detection of a coetary aminoacid.

The plant pathogenic rust fungi colonize leaf tissue and feed off their host plants without killing them. Certain economically important species of different genera such as Melampsora, Phakopsora, Puccinia, or Uromyces are extensively studied for resolving the mechanisms of the obligate biotrophy. As obligate parasites rust fungi only can complete their life cycle on living hosts where they grow through the leaf tissue by developing an extended network of intercellular hyphae from which intracellular haustoria are differentiated. Haustoria are involved in key functions of the obligate biotrophic lifestyle: suppressing host defense responses and acquiring nutrients. This review provides a survey of rust fungi nitrogen nutrition with special emphasis on aminoacid uptake. A variety of sequences of aminoacid transporter genes of rust fungi have been published; however, transport activity of only three in planta highly up-regulated aminoacid permeases have been characterized. Functional and immunohistochemical investigations have shown the specificity and localization of these transporters. Sequence data of various genome projects allowed identification of numerous rust aminoacid transporter genes. An in silico analysis reveals that these genes can be classified into different transporter families. In addition, genetic and molecular data of aminoacid transporters have provided new insights in the corresponding metabolic pathways.

to the coastal sedimentary humic acids implying higher association of aminoacids with the carbonaceous and fine grained sedimentary humic acids. Both the humic and fulvic acids are composed of neutral, acidic, basic, aromatic and sulphur containing aminoacids....

This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic aminoacids as a function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of four. This is done both for a strict definition of aliphatic aminoacids only involving carbon and hydrogen atoms in their side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic aminoacids, we also give several examples of non-proteinogenic aliphatic aminoacids, playing a role, for instance, in signalling. The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity arises from the multifarious combination of building blocks.

This invention provides compositions and methods for producing translational components that expand the number of genetically encoded aminoacids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, pairs of tRNAs/synthetases and unnatural aminoacids. Proteins and methods of producing proteins with unnatural aminoacids in eukaryotic cells are also provided.

This invention provides compositions and methods for producing translational components that expand the number of genetically encoded aminoacids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural aminoacids. Proteins and methods of producing proteins with unnatural aminoacids in eukaryotic cells are also provided.

Aminoacids, proteins and hydrolysates of proteins have been known to protect edible oils from oxidation. While aminoacids and related materials have high potential as antioxidants for frying oil, effectiveness of each aminoacid and mechanisms of their activities are not well understood yet. Propo...

Full Text Available The role of aminoacids as substrates for protein synthesis is well documented. However, a function for aminoacids in modulating the signal transduction pathways that regulate mRNA translation has only recently been described. Interesting, some of the signaling pathways regulated by aminoacids overlap with those classically associated with the cellular response to hormones such as insulin and insulin-like growth factors. The focus of this review is on the signaling pathways regulated by aminoacids, with a particular emphasis on the branched-chain aminoacid leucine, and the steps in mRNA translation controlled by the signaling pathways.

Aminoacids play important roles in both human and animal nutrition and in the maintenance of health. Here, aminoacids are classified into three groups: first, essential aminoacids, which are essential to nutrition; second, functional aminoacids, recently found to be important in the promotion of physiological functions; and third, dipeptides, which are used to resolve problematic features of specific free aminoacids, such as their instability or insolubility. This review focusses on recent researches concerning the microbial production of essential aminoacids (lysine and methionine), functional aminoacids (histidine and ornithine), and a dipeptide (L-alanyl-L-glutamine).

Composition of aminoacids, fatty acids and dietary fibre monomers in kernels of ... Nuts are rich in protein and essential aminoacids, and have a high energy value ... of protein, especially when combined with foods with high lysine content.

Full Text Available That aminoacid properties are responsible for the way protein molecules evolve is natural and is also reasonably well supported both by the structure of the genetic code and, to a large extent, by the experimental measures of the aminoacid similarity. Nevertheless, there remains a significant gap between observed similarity matrices and their reconstructions from aminoacid properties. Therefore, we introduce a simple theoretical model of aminoacid similarity matrices, which allows splitting the matrix into two parts - one that depends only on mutabilities of aminoacids and another that depends on pairwise similarities between them. Then the new synthetic aminoacid properties are derived from the pairwise similarities and used to reconstruct similarity matrices covering a wide range of information entropies. Our model allows us to explain up to 94% of the variability in the BLOSUM family of the aminoacids similarity matrices in terms of aminoacid properties. The new properties derived from aminoacid similarity matrices correlate highly with properties known to be important for molecular evolution such as hydrophobicity, size, shape and charge of aminoacids. This result closes the gap in our understanding of the influence of aminoacids on evolution at the molecular level. The methods were applied to the single family of similarity matrices used often in general sequence homology searches, but it is general and can be used also for more specific matrices. The new synthetic properties can be used in analyzes of protein sequences in various biological applications.

The microbial biotechnology of aminoacids production which was developed and industrialized in Japan have been summarized. The aminoacids include L-glutamic acid, L-lysine, L-threonine, L-aspartic acid, L-alanine, L-cysteine, L-dihydroxyphenylalanine, D-p-hydroxyphenyl-glycine, and hydroxy-L-proline.

Analyses of two carbonaceous meteorites have provided much of the latest evidence which seems to support Oparin's theory on the origin of life. The meteorites involved are the Murray meteorite, which fell in 1950, and the Murchison meteorite, which fell in 1969. The aminoacids in the two meteorites are similar in composition. Eight of the twenty aminoacids found belong to aminoacids present in proteins. A number of monocarboxylic and dicarboxylic fatty acids were also found in the meteorites.

Misfolding of the prion protein (PrP) is the key step in the transmission of spongiform pathologies in humans and several animals. Although PrP is highly conserved in mammals, a few changes in the sequence of endogenous PrP are proposed to confer protection to dogs, which were highly exposed to prion during the mad-cow epidemics. D159 is a unique aminoacid found in PrP from dogs and other canines that was shown to alter surface charge, but its functional relevance has never been tested in vivo. Here, we show in transgenic Drosophila that introducing the N159D substitution on mouse PrP decreases its turnover. Additionally, mouse PrP-N159D demonstrates no toxicity and accumulates no pathogenic conformations, suggesting that a single D159 substitution is sufficient to prevent PrP conformational change and pathogenesis. Understanding the mechanisms mediating the protective activity of D159 is likely to lessen the burden of prion diseases in humans and domestic animals.

Full Text Available Glyphosate, the active ingredient in Roundup®, is the most popular herbicide used worldwide. The industry asserts it is minimally toxic to humans, but here we argue otherwise. Residues are found in the main foods of the Western diet, comprised primarily of sugar, corn, soy and wheat. Glyphosate's inhibition of cytochrome P450 (CYP enzymes is an overlooked component of its toxicity to mammals. CYP enzymes play crucial roles in biology, one of which is to detoxify xenobiotics. Thus, glyphosate enhances the damaging effects of other food borne chemical residues and environmental toxins. Negative impact on the body is insidious and manifests slowly over time as inflammation damages cellular systems throughout the body. Here, we show how interference with CYP enzymes acts synergistically with disruption of the biosynthesis of aromatic aminoacids by gut bacteria, as well as impairment in serum sulfate transport. Consequences are most of the diseases and conditions associated with a Western diet, which include gastrointestinal disorders, obesity, diabetes, heart disease, depression, autism, infertility, cancer and Alzheimer’s disease. We explain the documented effects of glyphosate and its ability to induce disease, and we show that glyphosate is the “textbook example” of exogenous semiotic entropy: the disruption of homeostasis by environmental toxins.

Indigenous aminoacids have been found indigenous all 8 carbonaceous chondrite groups. However, the abundances, structural, enantiomeric and isotopic compositions of aminoacids differ significantly among meteorites of different groups and petrologic types. This suggests that parent-body conditions (thermal or aqueous alteration), mineralogy, and the preservation of aminoacids are linked. Previously, elucidating specific relationships between aminoacids and mineralogy was not possible because the samples analyzed for aminoacids were much larger than the scale at which petrologic heterogeneity is observed (sub mm-scale differences corresponding to sub-mg samples). Recent advances in aminoacid measurements and application of techniques such as high resolution X-ray diffraction (HR-XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) for mineralogical characterizations allow us to perform coordinated analyses on the scale at which mineral heterogeneity is observed.

CR meteorites are among the most primitive meteorites. In this paper, we report the first measurements of aminoacids in Antarctic CR meteorites, two of which show the highest aminoacid concentrations ever found in a chondrite. EET92042, GRA95229 and GRO95577 were analyzed for their aminoacid content using high performance liquid chromatography with UV fluorescence detection (HPLC-FD) and gas chromatographymass spectrometry (GC-MS). Our data show that EET92042 and GRA95229 are the most aminoacid-rich chondrites ever analyzed, with total aminoacid concentrations ranging from 180 parts-per-million (ppm) to 249 ppm. GRO95577, however, is depleted in aminoacids. The most abundant aminoacids present in the EET92042 and GRA95229 meteorites are the alpha-aminoacids glycine, isovaline, alpha-aminoisobutyric acid (alpha-AIB), and alanine, with delta13C values ranging from +31.6per mil to +50.5per mil. The carbon isotope results together with racemic enantiomeric ratios determined for most aminoacids strongly i...

Knowledge of the aminoacid composition of foods is essential to calculate their chemical score, which is used to predict protein quality of foods and diets. Though aminoacid composition of many foods is reasonably well established, better knowledge is needed on native foods consumed in different regions and countries. This paper presents the aminoacid composition of different presentations of raw and processed foods produced and consumed in Mexico. The aminoacid composition was determined using Beckman aminoacid analyzers (models 116 and 6300). Tryptophan was determined using the Spies and Chambers method. Of the different foods analyzed, some comments are made on native or basic foods in Mexico: Spirulin, where lysine is the limiting aminoacid, with a chemical score of 67%, is a good source of tryptophan (1.16g/16 gN); amaranth contains high levels of sulphur aminoacids (4.09 to 5.34 g/16gN), with a protein content of 15 g/100g; and pulque, a Pre-Hispanic beverage that contains high levels of tryptophan (2.58 g/16 gN) and sulphur aminoacids (2.72 g/16 gN). Finally, insects are good sources of sulphur aminoacids and lysine.

Full Text Available PURPOSE: Recent studies have revealed that branched-chain aminoacids (BCAA reduce the development of hepatocellular carcinoma (HCC in patients with obesity and hepatitis C virus infection by improving insulin resistance (IR. The aim of this study was to examine the anti-cancer and anti-fibrotic effects of BCAA on the development of diethylnitrosamine (DEN-induced HCC and liver cirrhosis in a rat model. METHODS: Male SD rats received weekly intraperitoneal injections of DEN (50 mg/kg of body weight for 16 weeks to induce HCC. They were fed a diet containing 3% casein, 3% or 6% BCAA for 13 weeks beginning 6 weeks after DEN administration. DEN was used to induce HCC through stepwise development from cirrhosis to HCC. The effect of BCAA was evaluated in tumor tissues by histopathologic analyses, reverse transcription-polymerase chain reaction, and Western blotting. RESULTS: The mean area and number of dysplastic nodules (DNs and tumors in the casein group tended to be larger than those in the BCAA group 16 weeks after DEN administration. The mean fibrotic area in the BCAA group was smaller than that in the casein group. The BCAA group showed decreased mRNA levels for markers of fibrosis, angiogenesis, and apoptosis inhibition. Compared with the casein group, the BCAA group had lower levels of α-smooth muscle actin, vascular endothelial growth factor, p-β-catenin, p-p38 mitogen-activated protein kinase, proliferating cell nuclear antigen, and caspase-3 protein expression, as well as a higher level of cleaved caspase-3 protein expression. CONCLUSIONS: BCAA supplementation of the diet ameliorated liver fibrosis and HCC development in a DEN-induced rat model of HCC with liver cirrhosis, but not in the IR model. These results provide a rationale for anti-fibrosis and chemoprevention using BCAA treatment for HCC with liver cirrhosis, as well as decreasing the ammonia level.

In chronic hepatitis C virus (HCV) infection, it is thought that both chronic persistent inflammation and oxidative stress contribute to the development of hepatocellular carcinoma (HCC), and it has been reported that long-term oral supplementation with branched-chain aminoacid (BCAA) granules could inhibit liver carcinogenesis. However, the extent of the involvement of these factors remains obscure. To clarify the involvement of inflammation and oxidative stress in the inhibition of liver carcinogenesis, we evaluated the effect of oral administration of BCAA granules on oxidative stress and inflammation in HCV-positive patients with liver cirrhosis. Twenty-seven patients were enrolled in the study: 18 of the patients were treated with BCAA granules (administered group) and nine were observed without BCAA granules (non-administered group). In the non-administered group, the production of oxidative stress, as indicated by urine 8-hydroxydeoxyguanosine (8-OHdG) and 15-F2t-Isoprostane (8-IsoPs), significantly increased with time, while in the administered group the levels of ferritin and 8-OHdG decreased significantly. Comparison of the two groups demonstrated that highly sensitive CRP, ferritin, 8-OHdG and 8-IsoPs were significantly reduced by taking BCAA granules. The time-course analysis showed that ferritin and highly sensitive CRP seemed to decrease first, followed by a decrease of 8-OHdG and 8-IsoPs. These findings indicated that the administration of BCAA granules influenced microinflammation and the metabolism of iron in HCV-positive patients with liver cirrhosis, and subsequently seemed to reduce the production of oxidative stress, possibly leading to a decrease in the occurrence of HCC.

The administration of Domoic Acid (Dom) in a 0.2 mg/kg i.p. dose induces changes in the levels of aminoacids of neurochemical interest (Asp, Glu, Gly, Tau, Ala, GABA) in different rat brain regions (hypothalamus, hippocampus, amygdala, striatum, cortex and midbrain). The most affected aminoacid is the GABA, the main inhibitory aminoacid neurotransmitter, whereas glutamate, the main excitatory aminoacid, is not affected. The rat brain regions that seem to be the main target of the Dom action belong to the limbic system (hippocampus, amygdala). The possible implication of the aminoacids in the actions of Dom is also discussed.

The plasma amino acidfs of 17 patients were studied before and during total parenteral nutrition (TPN). The aminoacid (AA) pattern changed similarly for all patients. The AA concentration changes relative to preinfusion (PAER) were the most informative index of change. Two groups of AA were defined, the "branched chain" group (five aminoacids) and the "hepatic" group (four aminoacids) based on the correlation of PAER values. Comparison of PAER values with the ratio of AA intake to requirement indicated that the requirements of the sick patients were more similar to those of children than those of healthy adults.

This paper describes a method for determining the nutritional value of D-aminoacids, D-peptides, and aminoacid derivatives using a growth assay in mice fed a synthetic all-aminoacid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nutritionally essential aminoacid such as L-lysine (L-Lys), L-methionine (L-Met), L -phenylalanine (L-Phe), and L-tryptophan (L-Trp) as well as the semi-essential aminoacids L-cysteine (L-Cys) and L-tyrosine (L-Tyr). The results show wide-ranging variations in the biological utilization of test substances. The method is generally applicable to the determination of the biological utilization and safety of any aminoacid derivative as a potential nutritional source of the corresponding L-aminoacid. Because the organism is forced to use the D-aminoacid or aminoacid derivative as the sole source of the essential or semi-essential aminoacid being replaced, and because a free aminoacid diet allows better control of composition, the use of all-aminoacid for such determinations may be preferable to protein-based diets.

Three kinds of poly aminoacids, poly-γ-glutamic acid, poly(ε-L-lysine) and multi-L-arginyl-poly (L-aspartic acid) can be synthesized by enzymatic process independently from ribosomal protein biosynthesis pathways in microorganism. These biosynthesized polymers have attracted more and more attentions because of their unique properties and various applications. In this review, the current knowledge on the biosynthesis, biodegradations and applications of these three poly aminoacids are summarized.

Lactic streptococci are extremely fastidious bacteria. For growth an exogenous source of aminoacids and other nutrients is essential. The aminoacid requirement in milk is fulfilled by the milk-protein casein, which is degraded by sequential hydrolysis, involving proteases and peptidases. ... Zie:

Reductions in dietary protein level and supplementation with certain crystalline aminoacids is a well-established method of formulating diets to achieve a more ideal aminoacid pattern and to reduce nitrogen excretion. Up to 35% reduction in nitrogen excretion may be achieved by supplementing pig

Reductions in dietary protein level and supplementation with certain crystalline aminoacids is a well-established method of formulating diets to achieve a more ideal aminoacid pattern and to reduce nitrogen excretion. Up to 35% reduction in nitrogen excretion may be achieved by supplementing pig d

Discusses the determination of hydrolyzable aminoacid precursors and a group of six aminoacids in the returned lunar samples of the Apollo programs. Indicates that molecular evolution is arrested at the precursor stage on the Moon because of lack of water. (CC)

In recent years, β-aminoacids and their derivatives have attracted considerable attention due to their occurrence in biologically active natural products, such as dolastatins,cyclohexylnorstatine and Taxol. β-Aminoacids also find application in the synthesis of β-lactams,piperidines, indolizidines. Moreover, the peptides consisting of β-aminoacids, the so-called β-peptides, have been extensively studied recently. Consequently, considerable efforts have been directed to the synthesis of β-aminoacids and their derivatives1. In particular, stereoselective synthesis of β-aminoacids has been a challenging project, and there are only limited methods available. In this presentation, we report our efforts in this area.

Plants are a rich source of aminoacids and their individual abundance in plants is of great significance especially in terms of food. Therefore, it is of utmost necessity to create a database of the relative aminoacid contents in plants as reported in literature. Since in most of the cases complete analysis of profiles of aminoacids in plants was not reported, the units used and the methods applied and the plant parts used were different, aminoacid contents were converted into relative units with respect to lysine for statistical analysis. The most abundant aminoacids in plants are glutamic acid and aspartic acid. Pearson's correlation analysis among different aminoacids showed that there were no negative correlations between the aminoacids. Cluster analysis (CA) applied to relative aminoacid contents of different families. Alismataceae, Cyperaceae, Capparaceae and Cactaceae families had close proximity with each other on the basis of their relative aminoacid contents. First three components of principal component analysis (PCA) explained 79.5% of the total variance. Factor analysis (FA) explained four main underlying factors for aminoacid analysis. Factor-1 accounted for 29.4% of the total variance and had maximum loadings on glycine, isoleucine, leucine, threonine and valine. Factor-2 explained 25.8% of the total variance and had maximum loadings on alanine, aspartic acid, serine and tyrosine. 14.2% of the total variance was explained by factor-3 and had maximum loadings on arginine and histidine. Factor-4 accounted 8.3% of the total variance and had maximum loading on the proline aminoacid. The relative content of different aminoacids presented in this paper is alanine (1.4), arginine (1.8), asparagine (0.7), aspartic acid (2.4), cysteine (0.5), glutamic acid (2.8), glutamine (0.6), glycine (1.0), histidine (0.5), isoleucine (0.9), leucine (1.7), lysine (1.0), methionine (0.4), phenylalanine (0.9), proline (1.1), serine (1.0), threonine (1

Bicyclic acidicaminoacids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new aminoacids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

In this review, we report the most important contributions in the structure, synthesis, physicochemical (surface adsorption, aggregation and phase behaviour) and biological properties (toxicity, antimicrobial activity and biodegradation) of Gemini natural aminoacid-based surfactants, and some potential applications, with an emphasis on the use of these surfactants as non-viral delivery system agents. Gemini surfactants derived from basic (Arg, Lys), neutral (Ser, Ala, Sar), acid (Asp) and sulphur containing aminoacids (Cys) as polar head groups, and Geminis with aminoacids/peptides in the spacer chain are reviewed.

The invention provides novel aminoacid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features aminoacid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred aminoacid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred aminoacid compound is [{sup 18}F]-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an {alpha}-aminoacid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of {alpha}-aminoisobutyric acid.

The invention provides novel aminoacid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features aminoacid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred aminoacid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred aminoacid compound is ›.sup.18 F!-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an .alpha.-aminoacid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of .alpha.-aminoisobutyric acid.

The invention provides novel aminoacid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features aminoacid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred aminoacid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred aminoacid compound is ›.sup.18 F!-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an .alpha.-aminoacid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of .alpha.-aminoisobutyric acid.

The invention provides novel aminoacid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features aminoacid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred aminoacid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred aminoacid compound is [{sup 18}F]-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an {alpha}-aminoacid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of {alpha}-aminoisobutyric acid.

A suite of protein and nonprotein aminoacids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, β -alanine, and γ -amino-n-butyric acid (γ -ABA) were the most abundant aminoacids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The aminoacid distribution in Nakhla, including the D/L ratios (values range from contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth.

Jul 9, 2014 ... of the three LAB strains to utilize aminoacids for growth and lactic acid production were employed to ... Lactic acid bacteria (LAB), which are used for the ..... and characterization of potential probiotic lactobacilli from pig feces.

It is likely that a variety of aminoacids existed in the early oceans of the Earth at the time of the origin and early evolution of life. "Primordial soup", hydrothermal vent, and meteorite based processes could have contributed to such an inventory. Several "protein" aminoacids were likely present, however, based on prebiotic synthesis experiments and carbonaceous meteorite studies, non-protein aminoacids, which are rare on Earth today, were likely the most abundant. An important uncertainty is the length of time these aminoacids could have persisted before their destruction by abiotic and biotic processes. Prior to life, aminoacid concentrations in the oceans were likely regulated by circulation through hydro-thermal vents. Today, the entire ocean circulates through vent systems every 10(exp 7) years. On the early Earth, this value was likely smaller due to higher heat flow and thus marine aminoacid life-time would have been shorter. After life, aminoacids in the oceans could have been assimilated by primitive organisms.

Dietary intake of L-aminoacids impacts on several physiological functions, including the control of gastrointestinal motility, pancreatic secretion, and appetite. However, the biological mechanisms regulating behavioral predilections for certain aminoacid types remain poorly understood. We tested the hypothesis that, in mice, the potency with which a given glucogenic aminoacid increases glucose utilization reflects its rewarding properties. We have found that: 1. During long-, but not short-, term preference tests, L-alanine and L-serine were preferred over their D-enantiomer counterparts, while no such effect was observed for L-threonine vs. D-threonine; 2. These behavioral patterns were closely associated with the ability of L-aminoacids to promote increases in respiratory exchange ratios such that those, and only those, L-aminoacids able to promote increases in respiratory exchange ratios were preferred over their D-isomers; 3. These behavioral preferences were independent of gustatory influences, since taste-deficient Trpm5 knockout mice displayed ingestive responses very similar to those of their wild-type counterparts. We conclude that the ability to promote increases in respiratory exchange ratios enhances the reward value of nutritionally relevant aminoacids, and suggest a mechanistic link between substrate utilization and aminoacid preferences. PMID:24072505

One of the most eagerly studied questions upon initial return of lunar samples was whether significant amounts of organic compounds, including aminoacids, were present. Analyses during the 1970s produced only tentative and inconclusive identifications of indigenous aminoacids. Those analyses were hampered by analytical difficulties including relative insensitivity to certain compounds, the inability to separate chiral enantiomers, and the lack of compound-specific isotopic measurements, which made it impossible to determine whether the detected aminoacids were indigenous to the lunar samples or the results of contamination. Numerous advances have been made in instrumentation and methodology for aminoacid characterization in extraterrestrial samples in the intervening years, yet the origin of aminoacids in lunar regolith samples has been revisited only once for a single lunar sample, (3) and remains unclear. Here, we present initial data from the analyses of aminoacid abundances in 12 lunar regolith samples. We discuss these abundances in the context of four potential aminoacid sources: (1) terrestrial biological contamination; (2) contamination from lunar module (LM) exhaust; (3) derivation from solar windimplanted precursors; and (4) exogenous delivery from meteorites.

Dietary intake of L-aminoacids impacts on several physiological functions, including the control of gastrointestinal motility, pancreatic secretion, and appetite. However, the biological mechanisms regulating behavioral predilections for certain aminoacid types remain poorly understood. We tested the hypothesis that, in mice, the potency with which a given glucogenic aminoacid increases glucose utilization reflects its rewarding properties. We have found that: (1) during long-, but not short-, term preference tests, L-alanine and L-serine were preferred over their D-enantiomer counterparts, while no such effect was observed for L-threonine vs. D-threonine; (2) these behavioral patterns were closely associated with the ability of L-aminoacids to promote increases in respiratory exchange ratios such that those, and only those, L-aminoacids able to promote increases in respiratory exchange ratios were preferred over their D-isomers; (3) these behavioral preferences were independent of gustatory influences, since taste-deficient Trpm5 knockout mice displayed ingestive responses very similar to those of their wild-type counterparts. We conclude that the ability to promote increases in respiratory exchange ratios enhances the reward value of nutritionally relevant aminoacids and suggest a mechanistic link between substrate utilization and aminoacid preferences.

Aminoacids are among the most important prebiotic molecules as it is from these precursors that the building blocks of life were formed [1]. Although organic molecules were among the components of the planetesimals making up the terrestrial planets, large amounts of primitive organic precursor molecules are believed to be exogenous in origin and to have been imported to the Earth via micrometeorites, carbonaceous meteorites and comets, especially during the early stages of the formation of the Solar System [1,2]. Our study concerns the hypothesis that prebiotic organic matter, present on Earth, was synthesized in the interstellar environment, and then imported to Earth by meteorites or micrometeorites. We are particularly concerned with the formation and fate of aminoacids. We have already shown that aminoacid synthesis is possible inside cometary grains under interstellar environment conditions [3]. We are now interested in the effects of space conditions and meteoritic impact on these aminoacids [4-6]. Most of the extraterrestrial organic molecules known today have been identified in carbonaceous chondrite meteorites [7]. One of the components of these meteorites is a clay with a composition close to that of saponite, used in our experiments. Two American teams have studied the effects of impact on various aminoacids [8,9]. [8] investigated aminoacids in saturated solution in water with pressure ranges between 5.1 and 21 GPa and temperature ranges between 412 and 870 K. [9] studied aminoacids in solid form associated with and without minerals (Murchison and Allende meteorite extracts) and pressure ranges between 3 and 30 GPa. In these two experiments, the aminoacids survived up to 15 GPa. At higher pressure, the quantity of preserved aminoacids decreases quickly. Some secondary products such as dipeptides and diketopiperazins were identified in the [8] experiment.

The effects of glucagon deficiency and excess on plasma concentrations of 21 aminoacids were studied in six normal human subjects for 8 h. During glucagon deficiency, produced by intravenous infusion of somatostatin (0.5 mg/h) and insulin (5 mU/kg per h), aminoacid concentration (sum of 21 aminoacids) rose from 2,607 +/- 76 to 2,922 +/- 133 microM after 4 h (P less than 0.025). The largest increases occurred in lysine (+26%), glycine (+24%), alanine (+23%), and arginine (+23%) concentratio...

A suite of protein and nonprotein aminoacids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, beta-alanine, and gamma-amino-n-butyric acid (gamma-ABA) were the most abundant aminoacids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The aminoacid distribution in Nakhla, including the D/L ratios (values range from meteorite soon after its fall to Earth, although it is possible that some of the aminoacids are endogenous to the meteorite. The rapid aminoacid contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth.

Cucumber mosaic virus (CMV) 2b suppresses RNA silencing primarily through the binding of double-stranded RNA (dsRNA) of varying sizes. However, the biologically active form of 2b remains elusive. Here, we demonstrate that the single and double alanine substitution mutants in the N-terminal 15th leucine and 18th methionine of CMV 2b exhibit drastically attenuated virulence in wild-type plants, but are efficiently rescued in mutant plants defective in RNA-dependent RNA polymerase 6 (RDR6) and Dicer-like 4 (DCL4). Moreover, the transgenic plants of 2b, but not 2blm (L15A/M18A), rescue the high infectivity of CMV-Δ2b through the suppression of antiviral silencing. L15A, M18A or both weaken 2b suppressor activity on local and systemic transgene silencing. In contrast with the high affinity of 2b to short and long dsRNAs, 2blm is significantly compromised in 21-bp duplex small interfering RNA (siRNA) binding ability, but maintains a strong affinity for long dsRNAs. In cross-linking assays, 2b can form dimers, tetramers and oligomers after treatment with glutaraldehyde, whereas 2blm only forms dimers, rather than tetramers and oligomers, in vitro. Together, these findings suggest that L15 and M18 of CMV 2b are required for high affinity to ds-siRNAs and oligomerization activity, which are essential for the suppression activity of 2b on antiviral silencing.

Although phase transformation is suggested as a key step in biomineralization, the chemical scenario about how organic molecules mediate inorganic phase transformations is still unclear. The inhibitory effect of aminoacids on hydroxyapatite (HAP, the main inorganic component of biological hard tissues such as bone and enamel) formation was concluded by the previous biomimetic modeling based upon direct solution crystallization. Here we demonstrate that acidicaminoacids, Asp and Glu, could promote HAP crystallization from its precursor crystal, brushite (DCPD). However, such a promotion effect could not be observed when the nonacidic aminoacids were applied in the transformation-based HAP formation. We found that the specific modification of acidicaminoacid on crystal-solution interfaces played a key role in the phase transition. The distinct properties between DCPD and HAP in the solution resulted in an interfacial energy barrier to suppress the spontaneous formation of HAP phase on DCPD phase. Different from the other aminoacids, the carboxylate-rich aminoacids, Asp and Glu, could modify the interfacial characteristics of these two calcium phosphate crystals to make them similar to each other. The experiments confirmed that the involvement of Asp or Glu reduced the interfacial energy barrier between DCPD and HAP, leading to a trigger effect on the phase transformation. An in-depth understanding about the unique roles of acidicaminoacids may contribute to understanding phase transformation controls druing biomineralization.

There has been a strong demand in Japan and East Asia for L-glutamic acid as a seasoning since monosodium glutamate was found to present umami taste in 1907. The discovery of glutamate fermentation by Corynebacterium glutamicum in 1956 enabled abundant and low-cost production of the aminoacid, creating a large market. The discovery also prompted researchers to develop fermentative production processes for other L-aminoacids, such as lysine. Currently, the aminoacid fermentation industry is so huge that more than 5 million metric tons of aminoacids are manufactured annually all over the world, and this number continues to grow. Research on aminoacid fermentation fostered the notion and skills of metabolic engineering which has been applied for the production of other compounds from renewable resources. The discovery of glutamate fermentation has had revolutionary impacts on both the industry and science. In this chapter, the history and development of glutamate fermentation, including the very early stage of fermentation of other aminoacids, are reviewed.

The sublimation of low ee aminoacids was examined while exploring simple mechanisms by which high ee aminoacids can be generated under conditions that exist in space; significant enantioenrichment of a variety of aminoacids by sublimation was achieved.

This study was intended to identify contents of aminoacids (AAs) of four commercial Nile fishes in. Sudan and to ... and Lysine-rich ingredients (fish meal, blood meal) are often expensive ... However, determination process of tryptophan from ...

Full Text Available Review is devoted to the aminoacids that could be used for nanostructures creation. The investigation of corresponding properties of aminoacids is essential for their role definition in creation of nanomedicines. However, aminoacid studying as components of nanostructures is insufficient. Study of nanoparticles for medicines creation was initiated by the development of nanotechnology. Aminoacids in complexes with the nanoparticles of organic and inorganic nature play an important role for medicines targeting in pathological process. They could reduce toxicity of the nanomaterials used in nanomedicine and are used for creation of biosensors, lab-on-chip and therefore they are a promising material for synthesis of new nanodrugs and diagnostic tools.

Full Text Available Aminoacids are not only building blocks for proteins but serve as precursors for the synthesis of many metabolites with multiple functions in growth and other biological processes of a living organism. The biosynthesis of aminoacids is tightly connected with central carbon, nitrogen and sulfur metabolism. Recent publication of genome sequences for two diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum created an opportunity for extensive studies on the structure of these metabolic pathways. Based on sequence homology found in the analyzed diatomal genes, the biosynthesis of aminoacids in diatoms seems to be similar to higher plants. However, one of the most striking differences between the pathways in plants and in diatomas is that the latter possess and utilize the urea cycle. It serves as an important anaplerotic pathway for carbon fixation into aminoacids and other N-containing compounds, which are essential for diatom growth and contribute to their high productivity.

Constraining the conformation of flexible peptides is a proven strategy to increase potency, selectivity, and metabolic stability. The focus has mostly been on constraining the backbone dihedral angles; however, the correct orientation of the aminoacid side chains (χ-space) that constitute...... the peptide pharmacophore is equally important. Control of χ-space utilizes conformationally constrained aminoacids that favor, disfavor, or exclude the gauche (-), the gauche (+), or the trans conformation. In this review we focus on cyclic aromatic aminoacids in which the side chain is connected...... to the peptide backbone to provide control of χ(1)- and χ(2)-space. The manifold applications for cyclized analogues of the aromatic aminoacids Phe, Tyr, Trp, and His within peptide medicinal chemistry are showcased herein with examples of enzyme inhibitors and ligands for G protein-coupled receptors....

The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural aminoacid L-(7-hydroxycoumarin-4-yl) ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural aminoacid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural aminoacid L-(7-hydroxycoumarin-4-yl)ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural aminoacid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

Laboratory experiments revealed that DL-methionine, sodium methionate, potassium methionate, and methionine hydroxyl analog at rates of 224 and 448 kg aminoacid/ha reduced the number of Belonolaimus longicaudatus mixed life-stages and Meloidogyne incognita J2 in soil, whereas L-threonine and lysine were not effective in reducing the number of either nematode. Futhermore, greenhouse experiments demonstrated that DL-methionine, sodium methionate, potassium methionate, and methionine hydroxyl analog were equally effective against B. longicaudatus at rates of 112, 224, and 448 kg aminoacid/ha, and the highest rate (448 kg aminoacid/ha) of all aminoacids was more effective in reducing the number of B. longicaudatus than the lower rate. However, phytotoxicity was observed on creeping bentgrass (Agrostis palustris) treated with 448 kg aminoacid/ha of methionine hydroxyl analog and DL methionine. In addition, in one of two field experiments on bermudagrass (Cynodon dactylon × C. transvaalensis) turf percentage green cover was increased and the number of B. longicaudatus was reduced by 224 kg aminoacid/ha of DL-methionine and potassium methionate compared to untreated controls in one of two trials.

The effect of three aminoacids on the growth of flue-cured tobacco was studied with water culture. The results showed that the three aminoacids improved the growth of flue-cured tobacco and increased the contents of chlorophyll a,chlorophyll b and carotenoid in tobacco. At the same time, the activities of NR (nitrate reductase), INV(invertase) and root growth activity were also significantly enhanced. The exogenous glutamic, aspartate and phenylalanine all increased the aminoacid contents of tobacco leaves. Of these three aminoacids, glutamic had the greatest effect, the next was aspartate,and phenylalanine had the least effect. These three aminoacids all had significantly increased the accumulation of aminoacids in the leaves of individual plants of tobacco; and the magnitude of accumulation indicated aspartate ＞ glutamic ＞phenylalanine.

is also present after aminoacid ingestion is not known. OBJECTIVE: The objective of the study was to explore insulin secretion and incretin hormones after oral and iv aminoacid administration at matched total aminoacid concentrations in healthy subjects. DESIGN: An aminoacid mixture (Vaminolac......: Oral aminoacid mixture ingestion elicits a stronger insulin secretory response than iv aminoacid at matching aminoacid levels and this is associated with increased GIP level, suggesting that an incretin effect exists also after oral aminoacids, possibly mediated by GIP....

The synthesis Of L-2-amino-8-oxodecanoic acid (Aoda) is described. This is a rare aminoacid component of apicidins, a family of new cyclic tetrapeptides, inhibitors of histone deacetylase. Aoda was synthesised in seven steps from L-glutamic acid along with some derivatives. Universidad de Alcalá Fundación General de la Universidad de Alcalá FEDER

We had shown that aromatic aminoacid (phenylalanine, tyrosine, and tryptophan) supplementation prevented bone loss in an aging C57BL/6 mice model. In vivo results from the markers of bone breakdown suggested an inhibition of osteoclastic activity or differentiation. To assess osteoclastic differentiation, we examined the effects of aromatic aminoacids on early /structural markers as vitronectin receptor, calcitonin receptor, and carbonic anhydrase II as well as, late/functional differentiation markers; cathepsin K and matrix metalloproteinase 9 (MMP-9). Our data demonstrate that the aromatic aminoacids down-regulated early and late osteoclastic differentiation markers as measured by real time PCR. Our data also suggest a link between the vitronectin receptor and the secreted cathepsin K that both showed consistent effects to the aromatic aminoacid treatment. However, the non-attachment related proteins, calcitonin receptor, and carbonic anhydrase II, demonstrated less consistent effects in response to treatment. Our data are consistent with aromatic aminoacids down-regulating osteoclastic differentiation by suppressing remodeling gene expression thus contributing initially to the net increase in bone mass seen in vivo.

Composite hybrid gold crystals are of profound interest in various research areas ranging from materials science to biology. Their importance is due to their unique properties and potential implementation, for example in sensing or in bio-nanomedicine. Here we report on the formation of hybrid organic-metal composites via the incorporation of selected aminoacids histidine, aspartic acid, serine, glutamine, alanine, cysteine, and selenocystine into the crystal lattice of single crystals of gold. We used electron microscopy, chemical analysis and high-resolution synchrotron powder X ray diffraction to examine these composites. Crystal shape, as well as atomic concentrations of occluded aminoacids and their impact on the crystal structure of gold, were determined. Concentration of the incorporated aminoacid was highest for cysteine, followed by serine and aspartic acid. Our results indicate that the incorporation process probably occurs through a complex interaction of their individual functional groups with ...

To evaluate the aminoacid profile in a group of adolescents with anorexia nervosa, and to apply alternative ways of presenting and assessing results, so as to increase the information available for understanding the metabolic abnormalities developed in these patients. Plasma aminoacid concentrations of a random group of patients with anorexia nervosa compared with values obtained from a 'healthy' adolescent population. The study was performed at the tertiary children's Hospital Sant Joan de Deu. Female adolescents (n = 92, age: 15+/-1.8 y) at diagnosis of anorexia nervosa. Reference values for aminoacids were obtained from apparently healthy adolescents (by history and analytical data) who underwent presurgical analysis for minor operations. Plasma aminoacid concentrations were measured by ion exchange chromatography. Basic laboratory analysis, carnitine and IGF-I were also determined. In anorexic patients plasma concentrations of taurine, asparagine, glutamine, glycine, methionine, phenylalanine, ornithine, and histidine were significantly higher than reference values (Mann-Whitney, P anorexia nervosa. Although absolute aminoacid values cannot play a significant role in the assessment of nutritional status in this condition, the calculation of some ratios (Phe/Tyr, Met/Cys and Gly/Val) and the graphical representation of relative values may be useful. The plasma aminoacid profile in anorexia nervosa is different from those of other severe malnutrition states, showing a marasmic pattern of balanced protein-energy undernutrition. Cystine and arginine may be considered limiting aminoacids in this disease, and the consequences of their deficient concentrations for oxidative damage should be further evaluated.

A significant fraction of the Earth's prebiotic volatile inventory may have been delivered by asteroidal and cometary impacts during the period of heavy bombardment. The realization that comets are particularly rich in organic material seemed to strengthen this suggestion. Previous modeling studies, however, indicated that most organics would be entirely destroyed in large comet and asteroid impacts. The availability of new kinetic parameters for the thermal degradation of aminoacids in the solid phase made it possible to readdress this question. We present the results of new high-resolution hydrocode simulations of asteroid and comet impact coupled with recent experimental data for aminoacid pyrolysis in the solid phase. Differences due to impact velocity as well as projectile material have been investigated. Effects of angle of impacts were also addressed. The results suggest that some aminoacids would survive the shock heating of large (kilometer-radius) cometary impacts. At the time of the origins of life on Earth, the steady-state oceanic concentration of certain aminoacids (like aspartic and glutamic acid) delivered by comets could have equaled or substantially exceeded that due to Miller-Urey synthesis in a carbon dioxide-rich atmosphere. Furthermore, in the unlikely case of a grazing impact (impact angle around 5 degrees from the horizontal) an amount of some aminoacids comparable to that due to the background steady-state production or delivery would be delivered to the early Earth.

Full Text Available Abstract Background Sequence comparisons make use of a one-letter representation for aminoacids, the necessary quantitative information being supplied by the substitution matrices. This paper deals with the problem of finding a representation that provides a comprehensive description of aminoacid intrinsic properties consistent with the substitution matrices. Results We present a Euclidian vector representation of the aminoacids, obtained by the singular value decomposition of the substitution matrices. The substitution matrix entries correspond to the dot product of aminoacid vectors. We apply this vector encoding to the study of the relative importance of various aminoacid physicochemical properties upon the substitution matrices. We also characterize and compare the PAM and BLOSUM series substitution matrices. Conclusions This vector encoding introduces a Euclidian metric in the aminoacid space, consistent with substitution matrices. Such a numerical description of the aminoacid is useful when intrinsic properties of aminoacids are necessary, for instance, building sequence profiles or finding consensus sequences, using machine learning algorithms such as Support Vector Machine and Neural Networks algorithms.

Aminoacids represent basic elements of proteins, which as a main source of nutrition themselves serve as a major reserve for maintaining essential functions of humans as well as animals. Taking the recent state of scientific knowledge into account, the industrial sector of aminoacids is a priori "suitable" to a specific kind of an ecologically sound way of production, which is based on biotechnology. The following article may point out characteristics of this particular industrial sector and illustrates the applicability of the latest economic methods, founded on development of the discipline of bionics in order to describe economic aspects of aminoacids markets. The several biochemical and technological fields of application of aminoacids lead to specific market structures in high developed and permanently evolving systems. The Harvard tradition of industrial economics explains how market structures mould the behaviour of the participants and influences market results beyond that. A global increase in intensity of competition confirms the notion that the supply-side is characterised by asymmetric information in contrast to Kantzenbachs concept of "narrow oligopoly" with symmetrical shared knowledge about market information. Departing from this point, certain strategies of companies in this market form shall be derived. The importance of Research and Development increases rapidly and leads to innovative manufacturing methods which replace more polluting manufacturing processes like acid hydrolysis. In addition to these modifications within the production processes the article deals furthermore with the pricing based on product life cycle concept and introduces specific applications of tools like activity based costing and target costing to the field of aminoacid production. The authors come to the conclusion that based on a good transferability of latest findings in bionics and ecological compatibility competitors in aminoacids manufacturing are well advised

During the postprandial phase dietary proteins are digested to peptides and aminoacids and absorbed. Once absorbed the peptides are further hydrolyzed to aminoacids and transported to the tissues. These aminoacids are largely incorporated into body proteins. Not all aminoacids are, however,

We have previously described the potent and selective (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor agonist, (RS)-2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA), and the AMPA receptor antagonist (RS)-2-amino-3-[3-(carboxymethoxy)-5-methyl-4......-isoxazolyl]propionic acid (AMOA). Using these AMPA receptor ligands as leads, a series of compounds have been developed as tools for further elucidation of the structural requirements for activation and blockade of AMPA receptors. The synthesized compounds have been tested for activity at ionotropic...... excitatory aminoacid (EAA) receptors using receptor binding and electrophysiological techniques, and for activity at metabotropic EAA receptors using second messenger assays. Compounds 1 and 4 were essentially inactive. (RS)-2-Amino-3-[3-(2-carboxyethyl)-5-methyl-4-isoxazolyl]propionic acid (ACMP, 2...

raises TNF-α and IL-6 to moderate levels, has only identified IL-6 as a potent cytokine, decreasing systemic aminoacid levels and muscle protein metabolism. The marked decrease in circulatory and muscle aminoacid concentrations was observed with a concomitant reduction in both the rates of muscle...... of IL-6 on the regulation of muscle protein metabolism but indirectly via IL-6 reducing aminoacid availability. SUMMARY: Recent studies suggest that the best described cytokines TNF-α and IL-6 are unlikely to be the major direct mediators of muscle protein loss in inflammatory diseases. However...... protein synthesis and breakdown, that is, reduced turnover with a minor increase in net muscle degradation. Very similar observations have been made in models of acute inflammation, induced by high-dose endotoxin injection. However, these changes were suggested not to be attributed to a direct effect...

raises TNF-α and IL-6 to moderate levels, has only identified IL-6 as a potent cytokine, decreasing systemic aminoacid levels and muscle protein metabolism. The marked decrease in circulatory and muscle aminoacid concentrations was observed with a concomitant reduction in both the rates of muscle...... protein synthesis and breakdown, that is, reduced turnover with a minor increase in net muscle degradation. Very similar observations have been made in models of acute inflammation, induced by high-dose endotoxin injection. However, these changes were suggested not to be attributed to a direct effect...... of IL-6 on the regulation of muscle protein metabolism but indirectly via IL-6 reducing aminoacid availability. SUMMARY: Recent studies suggest that the best described cytokines TNF-α and IL-6 are unlikely to be the major direct mediators of muscle protein loss in inflammatory diseases. However...

NASA's Stardust spacecraft returned samples from comet 81 P/WiId 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and aminoacids, but the origin of these compounds (cometary vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these aminoacids to determine their origin, leading to the first detection of a cometary aminoacid.

At the Kennedy Centre for Phenylketonuria, Denmark, large neutral aminoacids (LNAAs) are being used to treat adult and adolescent patients who are nonadherent to dietary treatment for phenylketonuria (PKU). At the start of treatment, a patient must undergo dietary analysis and regular blood...... sampling to measure plasma aminoacid (AA) concentrations. The aim of this analysis and treatment is that the patient receives 25-30% of the daily protein requirement from LNAA supplementation and the remaining 70-75% from natural, low-phenylalanine proteins (although some patients have difficulties...

In this work we detail the mechanism by which alkali metal encapsulation inside an armchair (9,9) single walled carbon nanotube (SWNT) can affect external aminoacid interactions. Based on our analysis, several configurations revealed that the physical properties of the SWNT systems are modified by using an internally situated Li atom. Density-functional theory calculations reveal that the most favorable interactions of the SWNT system is with tryptophan, threonine and proline that can be directly correlated to the backbone geometry of the aminoacid species.

Natural poly(aminoacid)s are a group of poly(ionic) molecules (ionomers) with various biological functions and putative technical applications and play, therefore, an important role both in nature and in human life. Because of their biocompatibility and their synthesis from renewable resources, poly(aminoacid)s may be employed for many different purposes covering a broad spectrum of medical, pharmaceutical, and personal care applications as well as the domains of agriculture and of environmental applications. Biodegradability is one important advantage of naturally occurring poly(aminoacid)s over many synthetic polymers. The intention of this review is to give an overview about the enzyme systems catalyzing the initial steps in poly(aminoacid) degradation. The focus is on the naturally occurring poly(aminoacid)s cyanophycin, poly(epsilon-L-lysine) and poly(gamma-glutamic acid); but biodegradation of structurally related synthetic polyamides such as poly(aspartic acid) and nylons, which are known from various technical applications, is also included.

The purpose of this paper is: (1) to make a concise review of the published dietary requirements of fishes for aminoacids, (2) to describe recent findings at the Tunison Laboratory concerning aminoacid nutrition of trout, (3) to review specific signs of deficiency of aminoacids, and (4) to discuss use of the fish egg aminoacid pattern as a guideline to formulating new feeds or studying aminoacid requirements of fishes for which there is limited information on their quantitative requirements.

A general method for synthesis of 1,4-substituted imidazolones from aminoacids on solid support or in solution has been developed. Aminoacid derived 3-Boc-(1,3)-oxazinane (Box) protected amino aldehyde building blocks were coupled through urea bonds to the amino terminal of dipeptides or amino ...

Cells have a constant turnover of proteins that recycle most aminoacids over time. Net loss is mainly due to aminoacid oxidation. Homeostasis is achieved through exchange of essential aminoacids with non-essential aminoacids and the transfer of amino groups from oxidised aminoacids to aminoacid biosynthesis. This homeostatic condition is maintained through an active mTORC1 complex. Under aminoacid depletion, mTORC1 is inactivated. This increases the breakdown of cellular proteins through autophagy and reduces protein biosynthesis. The general control non-derepressable 2/ATF4 pathway may be activated in addition, resulting in transcription of genes involved in aminoacid transport and biosynthesis of non-essential aminoacids. Metabolism is autoregulated to minimise oxidation of aminoacids. Systemic aminoacid levels are also tightly regulated. Food intake briefly increases plasma aminoacid levels, which stimulates insulin release and mTOR-dependent protein synthesis in muscle. Excess aminoacids are oxidised, resulting in increased urea production. Short-term fasting does not result in depletion of plasma aminoacids due to reduced protein synthesis and the onset of autophagy. Owing to the fact that half of all aminoacids are essential, reduction in protein synthesis and aminoacid oxidation are the only two measures to reduce aminoacid demand. Long-term malnutrition causes depletion of plasma aminoacids. The CNS appears to generate a protein-specific response upon aminoacid depletion, resulting in avoidance of an inadequate diet. High protein levels, in contrast, contribute together with other nutrients to a reduction in food intake. PMID:28546457

The nucleoamino acids 1-(3'-amino,3'-carboxypropyl)uracil (3) and 9-(3'-amino,3'-carboxypropyl)adenine (4) have been prepared as (L)-en-antiomers and as racemic mixtures. When 3 or 4 is suspended in water and treated with N,N'-carbon-yldiimidazole, peptides are formed in good yield. The products formed from the (L)-enantiomers are hydrolyzed to the monomeric aminoacids by pronase. Attempts to improve the efficiency of these oligomerizations by including a polyuridylate template in the reaction mixture were not successful. Similarly, oligomers derived from the (L)-enantiomer of 3 did not act as templates to facilitate the oligomerization of 4.

Enhanced aminoacid catabolism is a common response to inflammation, but the immunologic significance of altered aminoacid consumption remains unclear. The finding that tryptophan catabolism helped maintain fetal tolerance during pregnancy provided novel insights into the significance of aminoacid metabolism in controlling immunity. Recent advances in identifying molecular pathways that enhance aminoacid catabolism and downstream mechanisms that affect immune cells in response to inflammatory cues support the notion that aminoacid catabolism regulates innate and adaptive immune cells in pathologic settings. Cells expressing enzymes that degrade aminoacids modulate antigen-presenting cell and lymphocyte functions and reveal critical roles for aminoacid- and catabolite-sensing pathways in controlling gene expression, functions, and survival of immune cells. Basal aminoacid catabolism may contribute to immune homeostasis that prevents autoimmunity, whereas elevated aminoacid catalytic activity may reinforce immune suppression to promote tumorigenesis and persistence of some pathogens that cause chronic infections. For these reasons, there is considerable interest in generating novel drugs that inhibit or induce aminoacid consumption and target downstream molecular pathways that control immunity. In this review, we summarize recent developments and highlight novel concepts and key outstanding questions in this active research field.

Full Text Available Abstract This is the third in a series of six articles to discuss the major classes of dietary supplements (vitamins; minerals; aminoacids; herbs or botanicals; metabolites, constituents/extracts, or combinations. The major focus is on efficacy of such dietary supplements to enhance exercise or sport performance.

Sublicons have been obtained. Sublicons are threadlike structures appearing during sublimation of frozen solutions of small concentrations, containing racemate mixture of aminoacids and nucleotides. It is suggested that close location of chains and their zonal distribution by the section of helix spire forming sublicon wall, should provide the formation of stereohomogenous and complementary successions of biomonomers of different clases.

The accurate formation of cognate aminoacyl-transfer RNAs (aa-tRNAs) is essential for the fidelity of translation.Most aminoacids are esterified onto their cognate tRNA isoacceptors directly by aa.tRNA synthetases.However,in the case of four aminoacids (Gin,Asn,Cys and Sec),aminoacyl-tRNAs are made through indirect pathways in many organisms across all three domains of life.The process begins with the charging ofnoncognate aminoacids to tRNAs by a specialized synthetase in the case of Cys-tRNAcys formation or by synthetases with relaxed specificity,such as the non-discriminating glutamyl-tRNA,non-discriminating aspartyl-tRNA and seryl-tRNA synthetases.The resulting misacylated tRNAs are then converted to cognate pairs through transformation of the aminoacids on the tRNA,which is catalyzed by a group of tRNA-dependent modifying enzymes,such as tRNA-dependent amidotransferases,Sep-tRNA:Cys-tRNA synthase,O-phosphoseryi-tRNA kinase and Sep-tRNA:Sec-tRNA synthase.The majority of these indirect pathways are widely spread in all domains of life and thought to be part of the evolutionary process.

A new chemical index-imbalance degree(IBD),was proposed on the basis of cluster analysis in multivariate statistical analysis to estimate the extent of aminoacid balance in protein.The range of IBD is between 0 and 1,successively corresponding to complete baance and entire imbalance for the aminoacid profile of a sample.The aminoacid increment model of IBD belongs to an asymmetrical maximum-type,and there is a high correlation between IBD and coefficient of variation(CV),The nutritional Value of individual feed can be ranked and clustered according to its IBD;and by calculating the IBD of amixed sample with two or more feedstuffs,it is possible theoretically to predict whether a synergetic phenomenon exists and when an optimal mutual complement can happen.If the conceptive frame of IBD extended,it can be used to study the balance of plement can happen.If the conceptive frame of IBD extended,it can be used to study the balance of nutrients besides aminoacids,and is helpful to realize the automatic distinction and selection in diet formulating.

Full Text Available Objective: To evaluate the aminoacid profile and quality indices of Clerodendrum volubile (C. volubile leaves. Methods: Dried leaves of C. volubile were blended, defatted and subjected to aminoacid analysis using the technicon sequential multi-sample aminoacid analyzer. The aminoacid quality indices which covers for chemical score, essential aminoacid index, nutritional index, true digestibility, protein digestibility corrected aminoacid score, and digestible indispensable aminoacid score were evaluated using standard formulas. Results: Aminoacid analysis revealed glutamic acid to have the highest concentration, with cysteine having the least. Aspartic acid had the highest chemical score, this was followed by glycine, histidine and arginine, respectively. The least scores were observed in serine and methionine. Glutamic acid had the highest value for true digestibility and protein digestibility corrected aminoacid score, with the least observed in cysteine. Digestible indispensable aminoacid score evaluation showed histidine to have the highest value for infants (birth to 6 months, threonine for children (6 months to 3 years, while isoleucine was observed to have the highest value for older children, adolescents and adults. The essential aminoacid index value was less than 4, while nutritional index value was less than 0.5. Conclusions: These results indicated the leaves of C. volubile as a potential source of aminoacids in the human diet as portrayed by its aminoacids profile and qualities.

Covering: up to January, 2014. We focus here on β-aminoacids as components of complex natural products because the presence of β-aminoacids produces structural diversity in natural products and provides characteristic architectures beyond those of ordinary α-L-aminoacids, thus generating significant and unique biological functions in nature. In this review, we first survey the known bioactive β-aminoacid-containing natural products including nonribosomal peptides, macrolactam polyketides, and nucleoside-β-aminoacid hybrids. Next, the biosynthetic enzymes that form β-aminoacids from α-aminoacids and the de novo synthesis of β-aminoacids are summarized. Then, the mechanisms of β-aminoacid incorporation into natural products are reviewed. Because it is anticipated that the rational swapping of the β-aminoacid moieties with various side chains and stereochemistries by biosynthetic engineering should lead to the creation of novel architectures and bioactive compounds, the accumulation of knowledge regarding β-aminoacid-containing natural product biosynthetic machinery could have a significant impact in this field. In addition, genome mining of characteristic β-aminoacid biosynthetic genes and unique β-aminoacid incorporation machinery could lead to the discovery of new β-aminoacid-containing natural products.

The aminoacid permeability of membranes is of interest because they are one of the key solutes involved in cell function. Membrane permeability coefficients (P) for aminoacid classes, including neutral, polar, hydrophobic, and charged species, have been measured and compared using a variety of techniques. Decreasing lipid chain length increased permeability slightly (5-fold), while variations in pH had only minor effects on the permeability coefficients of the aminoacids tested in liposomes. Increasing the membrane surface charge increased the permeability of aminoacids of the opposite charge, while increasing the cholesterol content decreased membrane permeability. The permeability coefficients for most aminoacids tested were surprisingly similar to those previously measured for monovalent cations such as sodium and potassium (approximately 10(-12)-10(-13) cm s-1). This observation suggests that the permeation rates for the neutral, polar and charged aminoacids are controlled by bilayer fluctuations and transient defects, rather than partition coefficients and Born energy barriers. Hydrophobic aminoacids were 10(2) more permeable than the hydrophilic forms, reflecting their increased partition coefficient values. External pH had dramatic effects on the permeation rates for the modified aminoacid lysine methyl ester in response to transmembrane pH gradients. It was established that lysine methyl ester and other modified short peptides permeate rapidly (P = 10(-2) cm s-1) as neutral (deprotonated) molecules. It was also shown that charge distributions dramatically alter permeation rates for modified di-peptides. These results may relate to the movement of peptides through membranes during protein translocation and to the origin of cellular membrane transport on the early Earth.

Corynebacterium glutamicum is the workhorse of the production of proteinogenic aminoacids used in food and feed biotechnology. After more than 50 years of safe aminoacid production, C. glutamicum has recently also been engineered for the production of aminoacid-derived compounds, which find various applications, e.g., as synthons for the chemical industry in several markets including the polymer market. The aminoacid-derived compounds such as non-proteinogenic ω-aminoacids, α,ω-diamines, and cyclic or hydroxylated aminoacids have similar carbon backbones and functional groups as their aminoacid precursors. Decarboxylation of aminoacids may yield ω-aminoacids such as β-alanine, γ-aminobutyrate, and δ-aminovalerate as well as α,ω-diamines such as putrescine and cadaverine. Since transamination is the final step in several aminoacid biosynthesis pathways, 2-keto acids as immediate aminoacid precursors are also amenable to production using recombinant C. glutamicum strains. Approaches for metabolic engineering of C. glutamicum for production of aminoacid-derived compounds will be described, and where applicable, production from alternative carbon sources or use of genome streamline will be referred to. The excellent large-scale fermentation experience with C. glutamicum offers the possibility that these aminoacid-derived speciality products may enter large-volume markets.

The delivery to the plasma membrane of the general aminoacid permease, Gap1p, of Saccharomyces cerevisiae is regulated by the quality of the nitrogen source in the growth medium. In an effort to define how different nitrogen sources control Gap1p sorting, we find that mutations in GDH1 and GLN1 that decrease the flux through the glutamate and glutamine synthesis pathways result in increased Gap1p sorting to the plasma membrane. Conversely, deletion of MKS1, which increases glutamate and glutamine synthesis, decreases Gap1p sorting to the plasma membrane. Glutamate and glutamine are not unusual in their ability to regulate Gap1p sorting, because the addition of all natural aminoacids and many aminoacid analogs to the growth medium results in increased Gap1p sorting to the vacuole. Importantly, aminoacids have the capacity to signal Gap1p sorting to the vacuole regardless of whether they can be used as a source of nitrogen. Finally, we show that rapamycin does not affect Gap1p sorting, indicating that Gap1p sorting is not directly influenced by the TOR pathway. Together, these data show that aminoacids are a signal for sorting Gap1p to the vacuole and imply that the nitrogen-regulated Gap1p sorting machinery responds to aminoacid-like compounds rather than to the overall nutritional status associated with growth on a particular nitrogen source.

Aminoacids have been utilized for the production of foods, animal feeds and pharmaceuticals. After the discovery of the glutamic acid-producing bacterium Corynebacterium glutamicum by Japanese researchers, the production of aminoacids, which are primary metabolites, has been achieved using various microbial cells as hosts. Recently, metabolic engineering studies on the rational design of aminoacid-producing microbial cells have been successfully conducted. Moreover, the technology of systems biology has been applied to metabolic engineering for the creation of aminoacid-producing microbial cells. Currently, new technologies including synthetic biology, single-cell analysis, and evolutionary engineering have been utilized to create aminoacid-producing microbial cells. In addition, useful compounds from aminoacids have been produced by microbial cells. Here, current researches into the metabolic engineering of microbial cells toward production of aminoacids and aminoacid-related compounds are reviewed.

Animals rely on their diet for aminoacids that they are incapable either of synthesizing or of synthesizing in sufficient quantities to meet metabolic needs. These are the so-called 'essential aminoacids'. This set of aminoacids is similar among the vertebrates and many of the invertebrates. Previously, no information was available for aminoacid synthesis by the most primitive invertebrates, the Cnidaria. The purpose of this study was to examine aminoacid synthesis by representative cnidarians within the Order Scleractinia. Three species of zooxanthellate reef coral, Montastraea faveolata, Acropora cervicornis and Porites divaricata, and two species of non-zooxanthellate coral, Tubastrea coccinea and Astrangia poculata, were incubated with 14C-labelled glucose or with the 14C-labelled aminoacids glutamic acid, lysine or valine. Radiolabel tracer was followed into protein aminoacids. A total of 17 aminoacids, including hydroxyproline, were distinguishable by the techniques used. Of these, only threonine was not found radiolabelled in any of the samples. We could not detect tryptophan or cysteine, nor distinguish between the aminoacid pairs glutamic acid and glutamine, or aspartic acid and asparagine. Eight aminoacids normally considered essential for animals were made by the five corals tested, although some of them were made only in small quantities. These eight aminoacids are valine, isoleucine, leucine, tyrosine, phenylalanine histidine, methionine and lysine. The ability of cnidarians to synthesize these aminoacids could be yet another indicator of a separate evolutionary history of the cnidarians from the rest of the Metazoa.

The aminoacid content of mozzarella (low moisture, part skim milk) and asadero cheeses was determined by the column chromatographic method. Data from the direct analyses of the mozzarella cheeses were compared with the calculated aminoacid composition reported in tables in Agriculture Handbook No. 8-1. Phenylalanine and tyrosine contents were found to be higher in the direct analyses than in the calculated data in Handbook No. 8-1 (1.390 gm and 1.127 gm for phenylalanine, and 1.493 gm and 1.249 gm for tyrosine per 100 gm edible portion, respectively). That is of particular concern in the dietary management of phenylketonuria, in which accuracy in computing levels of phenylalanine and tyrosine is essential.

Hydrophobic aminoacids interact with their chemical environment through a combination of electrostatic, hydrogen bonding, dipole, induced dipole, and dispersion forces. These interactions all have their own characteristic energy scale and distance dependence. The low-frequency (0.1-5 THz, 5-150 cm-1) vibrational modes of aminoacids in the solid state are a direct indicator of the interactions between the molecules, which include interactions between an aminoacid functional group and its surroundings. This information is central to understanding the dynamics and morphology of proteins. The alpha-carbon is a chiral center for all of the hydrophobic aminoacids, meaning that they exist in two forms, traditionally referred to as L- and D-enantiomers. This nomenclature indicates which direction the molecule rotates plane-polarized visible light (levorotory and dextrorotory). Chiral a-aminoacids in proteins are exclusively the L-variety In the solid state, the crystal lattice of the pure L-enantiomer is the mirror image of the D-enantiomer crystal lattice. These solids are energetically identical. Enantiomers also have identical spectroscopic properties except when the measurement is polarization sensitive. A mixture of equal amounts D- and L-aminoacid enantiomers can crystallize into a racemic (DL-) structure that is different from that of the pure enantiomers. Whether a solution of both enantiomers will crystallize into a racemic form or spontaneously resolve into a mixture of separate D- and L-crystals largely depends on the interactions between molecules available in the various possible configurations. This is an active area of research. Low-frequency vibrations with intermolecular character are very sensitive to changes in lattice geometry, and consequently the vibrational spectra of racemic crystals are usually quite distinct from the spectra of the crystals of the corresponding pure enantiomers in the far-infrared (far-IR). THz time-domain spectroscopy (THz

Recent improvements in laser ablation molecular beam Fourier transform microwave spectroscopy (LA-MB-FTMW) have allowed the investigation of glutamine (COOH-CH(NH2)-CH2-CH2-CONH2), a natural aminoacid with a long polar side chain. One dominant structure has been detected in the rotational spectrum. The nuclear quadrupole hyperfine structure of two 14N nuclei has been totally resolved allowing the conclusive identification of the observed species.

Numerous data from both epidemiological and experimental origins indicate that some alimentary proteins and aminoacids in supplements can modify the blood LDL cholesterol, HDL cholesterol and total cholesterol. After an initial approval of the health claim for soy protein consumption for the prevention of coronary heart disease, more recently it has been concluded from an overall analysis of literature that isolated soy protein with isoflavones only slightly decrease LDL and total cholesterol. Other plant extracts and also some proteins from animal origin have been reported to exert a lowering effect on blood cholesterol when compared with a reference protein (often casein). The underlying mechanisms are still little understood. Individual aminoacids and mixture of aminoacids have also been tested (mostly in animal studies) for their effects on cholesterol parameters and on cholesterol metabolism. Methionine, lysine, cystine, leucine, aspartate and glutamate have been tested individually and in combination in different models of either normo or hypercholesterolemic animals and found to be able to modify blood cholesterol and/or LDL cholesterol and/or HDL cholesterol. It is however not known if these results are relevant to human nutrition.

Aminoacidopathies are a group of rare and diverse disorders, caused by the deficiency of an enzyme or transporter involved in aminoacid metabolism. For most aminoacidopathies, dietary management is the mainstay of treatment. Such treatment includes severe natural protein restriction, combined with protein substitution with all aminoacids except the aminoacids prior to the metabolic block and enriched with the aminoacid that has become essential by the enzymatic defect. For some aminoacidopathies, supplementation of one or two aminoacids, that have not become essential by the enzymatic defect, has been suggested. This so-called single aminoacid supplementation can serve different treatment objectives, but evidence is limited. The aim of the present article is to provide a systematic review on the reasons for applications of single aminoacid supplementation in aminoacidopathies treated with natural protein restriction and synthetic aminoacid mixtures. PMID:24422943

In this paper, we report that diisopropyl phosphoryl aminoacid could be prepared with reasonable yields under solvent-free condition by adding aminoacid to the mixture of diisopropyl phosphite and N-chlorodiisopropylamine.

Exposure of food proteins to certain processing conditions induces two major chemical changes: racemization of all L-aminoacids (LAA) to D-aminoacids (DAA) and concurrent formation of crosslinked aminoacids such as lysinoalanine (LAL). The diet contains both processing-induced and naturally-form...

markdownabstract__Abstract__ Disorders of aminoacid metabolism or transport are most clearly expressed in urine. Nevertheless the interpretation of abnormalities in urinary aminoacid excretion remains difficult. An increase or decrease of almost every aminoacid in urine can be due to various eti

Full Text Available A series of aminoacid methyl ester hydrochlorides were prepared in good toexcellent yields by the room temperature reaction of aminoacids with methanol in thepresence of trimethylchlorosilane. This method is not only compatible with natural aminoacids, but also with other aromatic and aliphatic aminoacids.

In accordance with the second law of thermodynamics, the Universe as a whole tends to higher entropy. However, the sequence of far-from-equilibrium events that led to the emergence of life on Earth could have imposed order and complexity during the course of chemical reactions in the so-called primordial soup of life. Hence, we may expect to find characteristic profiles or biases in the prebiotic product mixtures, as for instance among the first aminoacids. Seeking to shed light on this hypothesis, we have designed a high performance computer program that simulates the spontaneous formation of the aminoacid monomers in closed environments. The program was designed in reference to a prebiotic scenario proposed by Sydney W. Fox. The aminoacid abundances and their polarities as the two principal biases were also taken into consideration. We regarded the computational model as exhaustive since 200,000 aminoacid dimers were formed by simulation, subsequently expressed in a vector and compared with the corresponding aminoacid dimers that were experimentally obtained by Fox. We found a very high similarity between the experimental results and our simulations.

This paper reviews and interprets a method for determining the nutritional value of D-aminoacids, D-peptides, and aminoacid derivatives using a growth assay in mice fed a synthetic all-aminoacid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nutritionally essential aminoacid such as L-lysine (L-Lys), L-methionine (L-Met), L-phenylalanine (L-Phe), and L-tryptophan (L-Trp) as well as the semi-essential aminoacids L-cysteine (L-Cys) and L-tyrosine (L-Tyr). The results show wide-ranging variations in the biological utilization of test substances. The method is generally applicable to the determination of the biological utilization and safety of any aminoacid derivative as a potential nutritional source of the corresponding L-aminoacid. Because the organism is forced to use the D-aminoacid or aminoacid derivative as the sole source of the essential or semi-essential aminoacid being replaced, and because a free aminoacid diet allows better control of composition, the use of all-amino-acid diets for such determinations may be preferable to protein-based diets. Also covered are brief summaries of the widely scattered literature on dietary and pharmacological aspects of 27 individual D-aminoacids, D-peptides, and isomeric aminoacid derivatives and suggested research needs in each of these areas. The described results provide a valuable record and resource for further progress on the multifaceted aspects of D-aminoacids in food and biological samples.

Absorption of free and peptide-bound aminoacids was investigated in a girl with Hartnup disorder aged 26 months. Plasma levels of aminoacids were followed after oral administration of (1) an aminoacid mixture simulating casein and (2) an equivalent dose of a partial enzymic hydrolysate of casein containing oligopeptides in addition to free aminoacids. The results suggested that many neutral aminoacids were poorly absorbed when given in the free form, but much more readily absorbed when given as peptides. Unexpectedly, the results also suggested that glutamic acid was poorly absorbed when given in the free form. The results obtained with threonine could not be interpreted. There was an increased renal clearance of many neutral aminoacids, including glycine, but clearance of proline was not increased. Most aminoacids with an increased renal clearance also appeared to be poorly absorbed when given by mouth in the free form.

Full Text Available Aminoacids show apparent propensities toward their neighbors. In addition to preferences of aminoacids for their neighborhood context, aminoacid substitutions are also considered to be context-dependent. However, context-dependence patterns of aminoacid substitutions still remain poorly understood. Using relative entropy, we investigated the neighbor preferences of 20 aminoacids and the context-dependent effects of aminoacid substitutions with protein sequences in human, mouse, and dog. For 20 aminoacids, the highest relative entropy was mostly observed at the nearest adjacent site of either N- or C-terminus except C and G. C showed the highest relative entropy at the third flanking site and periodic pattern was detected at G flanking sites. Furthermore, neighbor preference patterns of aminoacids varied greatly in different secondary structures. We then comprehensively investigated the context-dependent effects of aminoacid substitutions. Our results showed that nearly half of 380 substitution types were evidently context dependent, and the context-dependent patterns relied on protein secondary structures. Among 20 aminoacids, P elicited the greatest effect on aminoacid substitutions. The underlying mechanisms of context-dependent effects of aminoacid substitutions were possibly mutation bias at a DNA level and natural selection. Our findings may improve secondary structure prediction algorithms and protein design; moreover, this study provided useful information to develop empirical models of protein evolution that consider dependence between residues.

Aminoacids show apparent propensities toward their neighbors. In addition to preferences of aminoacids for their neighborhood context, aminoacid substitutions are also considered to be context-dependent. However, context-dependence patterns of aminoacid substitutions still remain poorly understood. Using relative entropy, we investigated the neighbor preferences of 20 aminoacids and the context-dependent effects of aminoacid substitutions with protein sequences in human, mouse, and dog. For 20 aminoacids, the highest relative entropy was mostly observed at the nearest adjacent site of either N- or C-terminus except C and G. C showed the highest relative entropy at the third flanking site and periodic pattern was detected at G flanking sites. Furthermore, neighbor preference patterns of aminoacids varied greatly in different secondary structures. We then comprehensively investigated the context-dependent effects of aminoacid substitutions. Our results showed that nearly half of 380 substitution types were evidently context dependent, and the context-dependent patterns relied on protein secondary structures. Among 20 aminoacids, P elicited the greatest effect on aminoacid substitutions. The underlying mechanisms of context-dependent effects of aminoacid substitutions were possibly mutation bias at a DNA level and natural selection. Our findings may improve secondary structure prediction algorithms and protein design; moreover, this study provided useful information to develop empirical models of protein evolution that consider dependence between residues.

Aminoacid composition of water-soluble and water-insoluble proteins of 8 strains of Tr. vaginalis is studied. 17 aminoacids are found in both protein hydrolyzates. Despite the complete coincidence of their qualitative compositions there are reliable differences in the quantitative contents of some aminoacids. Differences in the contents of main aminoacids of water-soluble proteins of different strains reflect the belonging of the latter to different sero-groups. No reliable differences in the quantitative contents of aminoacids of both water-soluble and water-insoluble proteins in strains belonging to one sero-group are recognised.

A key process in the development of new drugs is elucidation of the interaction between the drug molecule and the target protein. Such knowledge then makes it possible to make systematic structural modifications of the drug molecule to optimize the interaction. Many analytical techniques can be applied to proteins in solution such as circular dichroism, ultraviolet, and fluorescence spectroscopy but these all have limitations. In this paper, we investigate the feasibility of using relatively simple, visible light Raman spectroscopic methods to investigate aminoacids and related biopolymers.

UV photoinduced fragmentation of protonated aromatics aminoacids have emerged the last few years, coming from a situation where nothing was known to what we think a good understanding of the optical properties. We will mainly focus this review on the tryptophan case. Three groups have mostly done spectroscopic studies and one has mainly been involved in dynamics studies of the excited states in the femtosecond/picosecond range and also in the fragmentation kinetics from nanosecond to millisecond. All these data, along with high level ab initio calculations, have shed light on the role of the different electronic states of the protonated molecules upon the fragmentation mechanisms.

Aminoacid analysis of a meteorite fragment of asteroid 2008 TC3 called Almahata Sitta was carried out using reverse-phase liquid chromatography coupled with UV fluorescence detection and time-of-flight mass spectrometry (LC-FD/ToF-MS) as part of a sample analysis consortium. LC-FD/ToF-MS analyses of hot-water extracts from the meteorite revealed a complex distribution of two- to seven-carbon aliphatic aminoacids and one- to three-carbon amines with abundances ranging from 0.5 to 149 parts-per-billion (ppb). The enantiomeric ratios of the aminoacids alanine, R-amino-n-butyric acid (beta-ABA), 2-amino-2-methylbutanoic acid (isovaline), and 2-aminopentanoic acid (norvaline) in the meteorite were racemic (D/L approximately 1), indicating that these aminoacids are indigenous to the meteorite and not terrestrial contaminants. Several other non-protein aminoacids were also identified in the meteorite above background levels including alpha-aminoisobutyric acid (alpha-AIB), 4-amino-2- methylbutanoic acid, 4-amino-3-methylbutanoic acid, and 3-, 4-, and 5-aminopentanoic acid. The total abundances of isovaline and alpha-AIB in Almahata Sitta are 1000 times lower than the abundances of these aminoacids found in the CM carbonaceous chondrite Murchison. The extremely low abundances and unusual distribution of five carbon aminoacids in Almahata Sitta compared to Cl, CM, and CR carbonaceous chondrites may reflect extensive thermal alteration of aminoacids on the parent asteroid by partial melting during formation or subsequent impact shock heating. It is also possible that aminoacids were synthesized by catalytic reactions on the parent body after asteroid 2008 TC3 cooled to lower temperatures.

The compatibility of β-aminoacids with ribosomal translation was studied for decades, but it has been still unclear whether the ribosome can accept various β-aminoacids, and whether the ribosome can introduce multiple β-aminoacids in a peptide. In the present study, by using the Escherichia coli reconstituted cell-free translation system with a reprogramed genetic code, we screened β-aminoacids that give high single incorporation efficiency and used them to synthesize peptides containing multiple β-aminoacids. The experiments of single β-aminoacid incorporation into a peptide revealed that 13 β-aminoacids are compatible with ribosomal translation. Six of the tested β-aminoacids (βhGly, l-βhAla, l-βhGln, l-βhPhg, l-βhMet, and d-βhPhg) showed high incorporation efficiencies, and seven (l-βhLeu, l-βhIle, l-βhAsn, l-βhPhe, l-βhLys, d-βhAla, and d-βhLeu) showed moderate incorporation efficiencies; whereas no full-length peptide was produced using other β-aminoacids (l-βhPro, l-βhTrp, and l-βhGlu). Subsequent double-incorporation experiments using β-aminoacids with high single incorporation efficiency revealed that elongation of peptides with successive β-aminoacids is prohibited. Efficiency of the double-incorporation of the β-aminoacids was restored by the insertion of Tyr or Ile between the two β-aminoacids. On the basis of these experiments, we also designed mRNA sequences of peptides, and demonstrated the ribosomal synthesis of peptides containing different types of β-aminoacids at multiple positions.

Full Text Available Every protein has a biosynthetic cost to the cell based on the synthesis of its constituent aminoacids. In order to optimise growth and reproduction, natural selection is expected, where possible, to favour the use of proteins whose constituents are cheaper to produce, as reduced biosynthetic cost may confer a fitness advantage to the organism. Quantifying the cost of aminoacid biosynthesis presents challenges, since energetic requirements may change across different cellular and environmental conditions. We developed a systems biology approach to estimate the cost of aminoacid synthesis based on genome-scale metabolic models and investigated the effects of the cost of aminoacid synthesis on Saccharomyces cerevisiae gene expression and protein evolution. First, we used our two new and six previously reported measures of aminoacid cost in conjunction with codon usage bias, tRNA gene number and atomic composition to identify which of these factors best predict transcript and protein levels. Second, we compared aminoacid cost with rates of aminoacid substitution across four species in the genus Saccharomyces. Regardless of which cost measure is used, aminoacid biosynthetic cost is weakly associated with transcript and protein levels. In contrast, we find that biosynthetic cost and aminoacid substitution rates show a negative correlation, but for only a subset of cost measures. In the economy of the yeast cell, we find that the cost of aminoacid synthesis plays a limited role in shaping transcript and protein expression levels compared to that of translational optimisation. Biosynthetic cost does, however, appear to affect rates of aminoacid evolution in Saccharomyces, suggesting that expensive aminoacids may only be used when they have specific structural or functional roles in protein sequences. However, as there appears to be no single currency to compute the cost of aminoacid synthesis across all cellular and environmental

Free aminoacid and free D-aminoacid contents of milk samples with different microorganism numbers and composition of dairy products produced from them were examined. Total microorganism number of milk samples examined varied from 1.25x106 to 2.95x106. It was established that concentration of both free D-aminoacids and free L-aminoacids increased with an increase in microorganism number. However, increase in D-aminoacid contents was higher considering its proportion. There was a particula...

The effect of alkali treatment on the isomerization of aminoacids was investigated. The 100×D/(D+L) values of aminoacids from peptide increased with increase in the number of constituent aminoacid residues. Furthermore, the N-terminal aminoacid of a dipeptide was isomerized to a greater extent than the C-terminal residue.

Life expectancy in the U.S. and globally continues to increase. Despite increased life expectancy quality of life is not enhanced, and older adults often experience chronic age-related disease and functional disability, including frailty. Additionally, changes in body composition such as the involuntary loss of skeletal muscle mass (i.e. sarcopenia) and subsequent increases in adipose tissue can augment disease and disability in this population. Furthermore, increased oxidative stress and decreased antioxidant concentrations may also lead to metabolic dysfunction in older adults. Specific aminoacids, including leucine, cysteine and its derivative taurine, and arginine can play various roles in healthy aging, especially in regards to skeletal muscle health. Leucine and arginine play important roles in muscle protein synthesis and cell growth while cysteine and arginine play important roles in quenching oxidative stress. Evidence suggests that supplemental doses of each of these aminoacids may improve the aging phenotype. However, additional research is required to establish the doses required to achieve positive outcomes in humans.

Oxazoline-aminoacids (Xaa-Ozn) occur in natural peptides of potentially important bioactivity. The conformations of the model compounds: Ac-(S)-Ala-Ozn(4R-Me), Ac-(S)-Ala-Ozn(4S-Me), and (gauche+, gauche-, anti) Ac-(S)-Val-Ozn(4R-Me) were studied at meta-hybrid M06-2X/6-311++G(d,p) method including solvent effect. Boc-L-Ala-L-Ozn-4-COOMe and Boc-L-Val-L-Ozn-4-COOMe were synthesized and studied by FT-IR and NMR-NOE methods. The conformations in crystal state were gathered from the Cambridge Structural Data Base. The main conformational feature of the oxazoline aminoacids is the conformation β2 (ϕ,ψ ∼ -161°, -6°), which predominates in weakly polar environment and still is accessible in polar surrounding. The changes of the conformational preferences towards the conformations αR (ϕ,ψ ∼ -70°, -15°) and then β (ϕ,ψ ∼ -57°, -155°) are observed with increase of the environment polarity.

A wide variety of organic compounds have been found in extraterrestrial bodies such as comets and carbonaceous chondrites. It is plausible that these extraterrestrial bodies carried organic compounds such as aminoacids or their precursors to the early Earth. It is claimed, however, that these extraterrestrial organics were destroyed during impacts to the Earth. We therefore examined possible transformation of aminoacids and their precursors during high-velocity impacts by using a rail gun "HYPAC" in ISAS. Starting materials used in the impact experiments were (i) aqueous solution of glycine (10 mM or 1.0 M), and (ii) a mixture of ammonia, methanol and water. The target materials were sealed in stainless steel capsules, and shocked by impact with a polycarbonate projectile accelerated with "HYPAC" to the velocities of 2.5 - 7.0 km/s. A part of the products was acid-hydrolyzed. Both hydrolyzed an unhydrolyzed products were analyzed by mass spectrometry, high performance liquid chromatography and capillary electrophoresis and chromatography. When an aqueous solution containing ammonia, methanol and water was shocked by impact at the velocity of 6.4 km/s, a number of aminoacids (e.g., serine and glycine) were detected after hydrolysis. The present results suggest that aminoacid precursors could be formed during cometary impacts. When glycine solution was used as a starting material, about 40 % of glycine was recovered even after 6 km/s impact. Methylamine and ammonia, which are known as pyrolytic products of glycine, were detected, besides them, diketopiperazine and an unidentified product whose molecular weight was 134, were detected, while no glycine peptides were identified in them. It was shown that the impact processes resulted in the formation of aminoacid condensates. Thermal stability of glycine precursor is comparable with glycine. The present results suggest that organic material could survive and/or formed during an impact process. Most of organic

BACKGROUND: This study reports the effects of ingesting branched-chain aminoacids (leucine, valine, and isoleucine) on protein metabolism in four men. METHODS: To calculate leg protein synthesis and breakdown, we used a new model that utilized the infusion of L-[ring-13C6]phenylalanine and the sampling of the leg arterial-venous difference and muscle biopsies. In addition, protein-bound enrichments provided for the direct calculation of muscle fractional synthetic rate. Four control subjects ingested an equivalent amount of essential aminoacids (threonine, methionine, and histidine) to discern the effects of branched-chain aminoacid nitrogen vs the effects of essential aminoacid nitrogen. Each drink also included 50 g of carbohydrate. RESULTS: Consumption of the branched-chain and the essential aminoacid solutions produced significant threefold and fourfold elevations in their respective arterial concentrations. Protein synthesis and breakdown were unaffected by branched-chain aminoacids, but they increased by 43% (p < .05) and 36% (p < .03), respectively, in the group consuming the essential aminoacids. However, net leg balance of phenylalanine was unchanged by either drink. Direct measurement of protein synthesis by tracer incorporation into muscle protein (fractional synthetic rate) revealed no changes within or between drinks. Whole-body phenylalanine flux was significantly suppressed by each solution but to a greater extent by the branched-chain aminoacids (15% and 20%, respectively) (p < .001). CONCLUSIONS: These results suggest that branched-chain aminoacid ingestion suppresses whole-body proteolysis in tissues other than skeletal muscle in normal men.

The production of some nonproteinous, and lack of production of other proteinous, aminoacids in model prebiotic synthesis, along with the instability of glutamine and asparagine, suggest that not all of the 20 present day proteinous aminoacids gained entry into proteins directly from the primordial soup. Instead, a process of active co-evolution of the genetic code and its constituent aminoacids would have to precede the final selection of these proteinous amono acids.

The changes in the concentrations of plasma aminoacids do not always follow the flow-based metabolic pathway network. We have previously shown that there is a control-based network structure among plasma aminoacids besides the metabolic pathway map. Based on this network structure, in this study, we performed dynamic analysis using time-course data of the plasma samples of rats fed single essential aminoacid deficient diet. Using S-system model (conceptual mathematical model represented by power-law formalism), we inferred the dynamic network structure which reproduces the actual time-courses within the error allowance of 13.17%. By performing sensitivity analysis, three of the most dominant relations in this network were selected; the control paths from leucine to valine, from methionine to threonine, and from leucine to isoleucine. This result is in good agreement with the biological knowledge regarding branched-chain aminoacids, and suggests the biological importance of the effect from methionine to threonine.

CR meteorites are among the most primitive meteorites. We have performed pioneering work determining the compositional characteristics of aminoacids in this type of carbonaceous chondrites. We report the first measurements of aminoacids in Antarctic CR meteorites, two of which show the highest aminoacid concentrations ever found in a chondrite. We have analyzed the aminoacid content of the Antarctic CRs EET92042, GRA95229 and GRO95577 using high performance liquid chromatography with UV fluorescence detection (HPLC-FD) and gas chromatography-mass spectrometry (GC-MS). Additionally, compound-specific carbon isotopic measurements for most of the individual aminoacids from the EET92042 and GRA95229 meteorites were achieved by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Our data show that EET92042 and GRA95229 are the most aminoacid-rich chondrites ever analyzed, with total aminoacid concentrations of 180 and 249 parts-per-million (ppm), respectively. GRO95577, however, is depleted in aminoacids (determined for most aminoacids indicate that primitive organic matter was preserved in these meteorites. In addition, the relative abundances of α-AIB and β-alanine amongst Antarctic CR meteorites appear to correspond to the degree of aqueous alteration on their respective parent body. Investigating the abundances and isotopic composition of aminoacids in primitive chondrites helps to understand the role of meteorites as a source of extraterrestrial prebiotic organic compounds to the early Earth.

Until very recently, prebiotic aminoacids were believed to have been generated in the atmosphere of the early Earth, as successfully simulated by the Urey-Miller experiments. Two independent studies now identified ice photochemistry in the interstellar medium as a possible source of prebiotic aminoacids. Ultraviolet irradiation of ice mixtures containing identified interstellar molecules (such as H2O, CO2, CO, CH3OH, and NH3) in the conditions of vacuum and low temperature found in the interstellar medium generated aminoacid structures including glycine, alanine, serine, valine, proline, and aspartic acid. After warmup, hydrolysis and derivatization, our team was able to identify 16 aminoacids as well as furans and pyrroles. Enantioselective analyses of the aminoacids showed racemic mixtures. A prebiotic interstellar origin of aminoacid structures is now discussed to be a plausible alternative to the Urey-Miller mechanism.

The heating above 400 °C of serine, cysteine, selenocysteine and threonine leads to a complete decomposition of the aminoacids and to the formation in low yields of alanine for the three formers and of 2-aminobutyric acid for the latter. At higher temperature, this aminoacid is observed only when sublimable α-alkyl-α-aminoacids are present, and with an enantiomeric excess dependent on several parameters. Enantiopure or enantioenriched Ser, Cys, Sel or Thr is not able to transmit its enantiomeric excess to the aminoacid formed during its decomposition. The presence during the sublimation-decomposition of enantioenriched valine or isoleucine leads to the enantioenrichment of all sublimable aminoacids independently of the presence of many decomposition products coming from the unstable derivative. All these studies give information on a potentially prebiotic key-reaction of abiotic transformations between α-aminoacids and their evolution to homochirality.

Aminoacid analysis of a meteorite fragment of asteroid 2008 TC(sub 3) called Almahata Sitta was carried out using reverse-phase high-perfo rmance liquid chromatography coupled with UV fluorescence detection a nd time-of-flight mass spectrometry (HPLC-FD/ToF-MS) as part of a sam ple analysis consortium. HPLC analyses of hot-water extracts from the meteorite revealed a complex distribution of two- to six-carbon aliph atic aminoacids and one- to three carbon amines with abundances rang ing from 0.5 to 149 parts-per-billion (ppb). The enantiomeric ratios of the aminoacids alanine, Beta-amino-n-butyric acid (Beta-ABA), 2-amino-2- methylbutanoic acid (isovaline), and 2-aminopentanoic acid (no rvaline) in the meteorite were racemic (D/L approximately 1), indicat ing that these aminoacids are indigenous to the meteorite and not te rrestrial contaminants. Several other non-protein aminoacids were also identified in the meteorite above background levels including alpha -aminoisobutyric acid (alpha-AIB), 4-amino-2- methybutanoic acid, 4-a mino-3-methylbutanoic acid, and 3-, 4-, and 5-aminopentanoic acid. Th e total abundances of isovaline and AlB in Almahata Sitta are approximately 1000 times lower than the abundances of these aminoacids found in the CM carbonaceous meteorite Murchison. The extremely love abund ances and unusual distribution of five carbon aminoacids in Almahata Sitta compared to Cl, CM, and CR carbonaceous meteorites and may be due to extensive thermal alteration of aminoacids on the parent aster oid by partial melting during formation or impact shock heating.

Proteins are playing a vital role in maintaining the cellular integrity and function, as well as for brain cells. Protein intake and supplementation of individual aminoacids can affect the brain functioning and mental health, and many of the neurotransmitters in the brain are made from aminoacids. The aminoacid supplementation has been found to reduce symptoms, as they are converted into neurotransmitters which in turn extenuate the mental disorders. The biosynthesis of aminoacids in the brain is regulated by the concentration of aminoacids in plasma. The brain diseases such as depression, bipolar disorder, schizophrenia, obsessive-compulsive disorder (OCD), and Alzheimer's (AD), Parkinson's (PD), and Huntington's diseases (HD) are the most common mental disorders that are currently widespread in numerous countries. The intricate biochemical and molecular machinery contributing to the neurological disorders is still unknown, and in this chapter, we revealed the involvement of dietary aminoacids on neurological diseases.

For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled aminoacids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common aminoacids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled aminoacids. By using the Oppolzer auxiliary, aminoacids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the {alpha}-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in aminoacids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common aminoacids.

All 20 natural aminoacids identification shows crucial importance in biochemistry and clinical application while it is still a challenge due to highly similarity in molecular configuration of the aminoacids. Low efficiency, complicated sensing molecules and environment hindered the successful identification. Here, we developed a facile sensor chip composed of one photochromic molecule with metal ions spotted to form spirooxazine-metallic complexes, and successfully recognized all the 20 natural aminoacids as well as their mixtures. The sensor chip gives distinct fluorescent fingerprint pattern of each aminoacid, based on multistate of spirooxazine under different light stimulations and discriminated interaction between various metal ions and aminoacids. The sensor chip demonstrates powerful capability of aminoacids identification, which promotes sensing of biomolecules.

After over 30 years of research, it was recently shown that nectar aminoacids increase female butterfly fecundity. However, little attention has been paid to the effect of nectar aminoacids on male butterfly reproduction. Here, we show that larval food conditions (nitrogen-rich vs. nitrogen-poor host plants) and adult diet quality (nectar with or without aminoacids) affected the amount of consumed nectar in Coenonympha pamphilus males. Furthermore, aminoacids in the nectar diet of males increased progeny's larval hatching mass, irrespective of paternal larval reserves. Our study takes the whole reproductive cycle of male butterflies into account, and also considers the role of females in passing male nutrients to offspring, as males' realized reproduction was examined indirectly via nuptial gifts, by female performance. With this comprehensive approach, we demonstrate for the first time that nectar aminoacids can improve male butterfly reproduction, supporting the old postulate that nectar aminoacids generally enhance butterfly fitness.

Aminoacids constitute an important fraction of the water-soluble organic nitrogen (WSON) compounds in aerosols and are involved in many processes in the atmosphere. In this work, we applied XPS to study aqueous solutions of four aminoacids: glycine, alanine, valine and methionine, in their zwitterionic forms. We found that aminoacids with hydrophilic side chains and smaller size, GLY and ALA, tend to stay in the bulk of the liquid, while the hydrophobic and bigger aminoacids, VAL and MET, are found to concentrate more on the surface. We found experimental evidences that the aminoacids have preferential orientation relative to the surface, with the hydrophobic side chain being closer to the surface than the hydrophilic carboxylate group. The observed aminoacid surface propensity has implications in atmospheric science as the surface interaction play a central role in cloud droplet formation, and they should be considered in climate models.

The existence of organic compounds on the lunar surface has been a question of interest from the Apollo era to the present. Investigations of aminoacids immediately after collection of lunar samples yielded inconclusive identifications, in part due to analytical limitations including insensitivity to certain compounds, an inability to separate enantiomers, and lack of compound-specific isotopic measurements. It was not possible to determine if the detected aminoacids were indigenous to the lunar samples or the result of terrestrial contamination. Recently, we presented initial data from the analysis of aminoacid abundances in 12 lunar regolith samples and discussed those results in the context of four potential aminoacid sources [5]. Here, we expand on our previous work, focusing on aminoacid abundances and distributions in seven regolith samples and presenting the first compound-specific carbon isotopic ratios measured for aminoacids in a lunar sample.

The content and composition of the aminoacids in typical chernozems were studied. The objects of the study included a reference soil under an old fallow and three variants under fodder crop rotations: not fertilized, with mineral fertilizers, and with organic fertilizers. The contents of 18 aminoacids were determined in these soils. The aminoacids were extracted by the method of acid hydrolysis and identified by the method of ion-exchange chromatography. The total content of most of the aminoacids was maximal in the reference soil; it was much lower in the cultivated soils and decreased in the following sequence: organic background > mineral background > no fertilization. The diversity of aminoacids was evaluated quantitatively using different parameters applied in ecology for estimating various aspects of the species composition of communities (Simpson, Margalef, Menhinick, and Shannon's indices). The diversity and contribution of different aminoacids to the total pool of aminoacids also varied significantly in the studied variants. The maximum diversity of aminoacids and maximum evenness of their relative abundance indices were typical of the reference chernozem; these parameters were lower in the cultivated soils. It was concluded that the changes in the structure of the aminoacids under the impact of agricultural loads are similar to those that are usually observed under stress conditions.

Full Text Available Relative to other nutrients, less is known about how animals sense aminoacids and how behaviour is organized accordingly. This is a significant gap in our knowledge because aminoacids are required for protein synthesis − and hence for life as we know it. Choosing Drosophila larvae as a case study, we provide the first systematic analysis of both the preference behaviour for, and the learning of, all 20 canonical aminoacids in Drosophila. We report that preference for individual aminoacids differs according to the kind of aminoacid, both in first-instar and in third-instar larvae. Our data suggest that this preference profile changes across larval instars, and that starvation during the third instar also alters this profile. Only aspartic acid turns out to be robustly attractive across all our experiments. The essentiality of aminoacids does not appear to be a determinant of preference. Interestingly, although aminoacids thus differ in their innate attractiveness, we find that all aminoacids are equally rewarding. Similar discrepancies between innate attractiveness and reinforcing effect have previously been reported for other tastants, including sugars, bitter substances and salt. The present analyses will facilitate the ongoing search for the receptors, sensory neurons, and internal, homeostatic aminoacid sensors in Drosophila.

Relative to other nutrients, less is known about how animals sense aminoacids and how behaviour is organized accordingly. This is a significant gap in our knowledge because aminoacids are required for protein synthesis - and hence for life as we know it. Choosing Drosophila larvae as a case study, we provide the first systematic analysis of both the preference behaviour for, and the learning of, all 20 canonical aminoacids in Drosophila We report that preference for individual aminoacids differs according to the kind of aminoacid, both in first-instar and in third-instar larvae. Our data suggest that this preference profile changes across larval instars, and that starvation during the third instar also alters this profile. Only aspartic acid turns out to be robustly attractive across all our experiments. The essentiality of aminoacids does not appear to be a determinant of preference. Interestingly, although aminoacids thus differ in their innate attractiveness, we find that all aminoacids are equally rewarding. Similar discrepancies between innate attractiveness and reinforcing effect have previously been reported for other tastants, including sugars, bitter substances and salt. The present analyses will facilitate the ongoing search for the receptors, sensory neurons, and internal, homeostatic aminoacid sensors in Drosophila.

We analyzed the aminoacid content of seven lunar regolith samples returned by the Apollo 16 and Apollo 17 missions and stored under NASA curation since collection using ultrahigh-performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Consistent with results from initial analyses shortly after collection in the 1970s, we observed aminoacids at low concentrations in all of the curated samples, ranging from 0.2 parts-per-billion (ppb) to 42.7 ppb in hot-water extracts and 14.5 ppb to 651.1 ppb in 6M HCl acid-vapor-hydrolyzed, hot-water extracts. Aminoacids identified in the Apollo soil extracts include glycine, D- and L-alanine, D- and L-aspartic acid, D- and L-glutamic acid, D- and L-serine, L-threonine, and L-valine, all of which had previously been detected in lunar samples, as well as several compounds not previously identified in lunar regoliths: -aminoisobutyric acid (AIB), D-and L-amino-n-butyric acid (-ABA), DL-amino-n-butyric acid, -amino-n-butyric acid, -alanine, and -amino-n-caproic acid. We observed an excess of the L enantiomer in most of the detected proteinogenic aminoacids, but racemic alanine and racemic -ABA were present in some samples.

Many human proteins contain consecutive aminoacid repeats, known as homopolymeric aminoacid (HPAA) tracts. Some inherited diseases are caused by proteins in which HPAAs are expanded to an excessive length. To this day, nine polyglutamine-related diseases and nine polyalanine-related diseases have been reported, including Huntington's disease and oculopharyngeal muscular dystrophy. In this study, potential HPAA-HPAA interactions were examined by yeast two-hybrid assays using HPAAs of approximately 30 residues in length. The results indicate that hydrophobic HPAAs interact with themselves and with other hydrophobic HPAAs. Previously, we reported that hydrophobic HPAAs formed large aggregates in COS-7 cells. Here, those HPAAs were shown to have significant interactions with each other, suggesting that hydrophobicity plays an important role in aggregation. Among the observed HPAA-HPAA interactions, the Ala28-Ala29 interaction was notable because polyalanine tracts of these lengths have been established to be pathogenic in several polyalanine-related diseases. By testing several constructs of different lengths, we clarified that polyalanine self-interacts at longer lengths (>23 residues) but not at shorter lengths (six to approximately 23 residues) in a yeast two-hybrid assay and a GST pulldown assay. This self-interaction was found to be SDS sensitive in SDS-PAGE and native-PAGE assays. Moreover, the intracellular localization of these long polyalanine tracts was also observed to be disturbed. Our results suggest that long tracts of polyalanine acquire SDS-sensitive self-association properties, which may be a prerequisite event for their abnormal folding. The misfolding of these tracts is thought to be a common molecular aspect underlying the pathogenesis of polyalanine-related diseases.

Full Text Available The hydrochloride of the racemic aminoacid (2-(7-hydroxycoumarin-4-ylethylglycine, which can serve as a fluorescent probe in proteins, and two halogen derivatives of it, were synthesized by using a new synthetic protocol in five steps. It is less costly and relatively easy to prepare this kind of fluorescent aminoacid with the new synthetic method. Furthermore, it can be applied to synthesize other derivatives of the coumarin aminoacid with some specific properties.

L-Aminoacid oxidases are flavoenzymes which catalyze the stereospecific oxidative deamination of an L-aminoacid substrate to a corresponding a-ketoacid with hydrogen peroxide and ammonia production. These enzymes, which are widely distributed in many different organisms, exhibit a marked affinity for hydrophobic aminoacids, including phenylalanine, tryptophan, tyrosine, and leucine. Snake venom LAAO induces platelet aggregation and cytotoxicity in various cancer cell lines. The enzyme has ...

Single nucleotide polymorphism (SNP) studies and random mutagenesis projects identify aminoacid substitutions in protein-coding regions. Each substitution has the potential to affect protein function. SIFT (Sorting Intolerant From Tolerant) is a program that predicts whether an aminoacid substitution affects protein function so that users can prioritize substitutions for further study. We have shown that SIFT can distinguish between functionally neutral and deleterious aminoacid changes in...

@@ β-hydroxy-α-aminoacids constitute an important class of compounds as naturally occurring aminoacids and as components of many complex natural products possessing a wide range of biological activities. [1] As a consequence of the essential role played by these aminoacids in the biological systems and their utility as synthetic building blocks, a number of useful strategies have been devised for their preparation. [2

Gas-phase acidities and heats of formation have been predicted at the G3(MP2)/SCRF-COSMO level of theory for 10 phosphorylated aminoacids and their corresponding amides, including phospho-serine (pSer), -threonine (pThr), and -tyrosine (pTyr), providing the first reliable set of these values. The gas-phase acidities (GAs) of the three named phosphorylated aminoacids and their amides have been determined using proton transfer reactions in a Fourier transform ion cyclotron mass spectrometer. Excellent agreement was found between the experimental and predicted GAs. The phosphate group is the deprotonation site for pSer and pThr and deprotonation from the carboxylic acid generated the lowest energy anion for pTyr. The infrared spectra were calculated for six low energy anions of pSer, pThr, and pTyr. For deprotonated pSer and pThr, good agreement is found between the experimental IRMPD spectra and the calculated spectra for our lowest energy anion structure. For pTyr, the IR spectra for a higher energy phosphate deprotonated structure is in good agreement with experiment. Additional experiments tested electrospray ionization (ESI) conditions for pTyr and determined that variations in solvent, temperature, and voltage can result in a different experimental GA value, indicating that ESI conditions affect the conformation of the pTyr anion.

Full Text Available Efficient and inexpensive methods are required for the high-throughput quantification of aminoacids in physiological fluids or microbial cell cultures. Here we develop an array of Escherichia coli biosensors to sensitively quantify eleven different aminoacids. By using online databases, genes involved in aminoacid biosynthesis were identified that - upon deletion - should render the corresponding mutant auxotrophic for one particular aminoacid. This rational design strategy suggested genes involved in the biosynthesis of arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, tryptophan, and tyrosine as potential genetic targets. A detailed phenotypic characterization of the corresponding single-gene deletion mutants indeed confirmed that these strains could neither grow on a minimal medium lacking aminoacids nor transform any other proteinogenic aminoacid into the focal one. Site-specific integration of the egfp gene into the chromosome of each biosensor decreased the detection limit of the GFP-labeled cells by 30% relative to turbidometric measurements. Finally, using the biosensors to determine the aminoacid concentration in the supernatants of two aminoacid overproducing E. coli strains (i.e. ΔhisL and ΔtdcC both turbidometrically and via GFP fluorescence emission and comparing the results to conventional HPLC measurements confirmed the utility of the developed biosensor system. Taken together, our study provides not only a genotypically and phenotypically well-characterized set of publicly available aminoacid biosensors, but also demonstrates the feasibility of the rational design strategy used.

Aminoacids are crucial for the cultivation of mammalian cells. This importance of aminoacids was realized soon after the development of the first cell lines, and a solution of a mixture of aminoacids has been supplied to cultured cells ever since. The importance of aminoacids is further pronounced in chemically defined mammalian cell culture media, making the consideration of their biological and chemical properties necessary. Aminoacids concentrations have been traditionally adjusted to their cellular consumption rates. However, since changes in the metabolic equilibrium of aminoacids can be caused by changes in extracellular concentrations, metabolomics in conjunction with flux balance analysis is being used in the development of culture media. The study of aminoacid transporters is also gaining importance since they control the intracellular concentrations of these molecules and are influenced by conditions in cell culture media. A better understanding of the solubility, stability, dissolution kinetics, and interactions of these molecules is needed for an exploitation of these properties in the development of dry powdered chemically defined media for mammalian cells. Due to the complexity of these mixtures however, this has proven to be challenging. Studying aminoacids in mammalian cell culture media will help provide a better understanding of how mammalian cells in culture interact with their environment. It would also provide insight into the chemical behavior of these molecules in solutions of complex mixtures, which is important in the understanding of the contribution of individual aminoacids to protein structure.

We isolated large quantities of mesophyll protoplasts from source and sink leaves of soybean plants and examined them for aminoacid uptake. Accumulation of aminoacids in isolated protoplasts was linear for at least 40 minutes. Uptake kinetics revealed the presence of both saturable and linear components. Increasing external pH decreases the uptake. The uncoupler, carbonyl cyanide p-trifluoromethoxyphenylhydrazone at 15 micromolar inhibited and fusicoccin at 10 micromolar stimulated aminoacid uptake. Our data are consistent with a proton-cotransport mechanism for the uptake of l-glutamine and alpha-amino isobutyric acid into soybean mesophyll cells.

Enantiomeric ratios of aminoacids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which aminoacids in sedimentary organic racemize abiotically. Based on a heating experiment, we report Arrhenius parameters...... between different aminoacids or depths. These results can be used in conjunction with measurements of sediment age to predict the ratio of D:L aminoacids due solely to abiotic racemization of the source material, deviations from which can indicate the abundance and turnover of active microbial...

Aspartie acid and glutamic acid with protected α-amino and α-carboxyl groups had been used to react with the activated hydroxyl group of N-substituted 3,4-fuUero pyrrolidine.The products were deprotected,affording two monofullerene α-aminoacids,monofullerene aspartic acid(mFas)and monofullerene glutamic acid(mFgu).Then a bifullerene glutamic acid conjugate (bFguC)was synthesized by reaction of mFgu containing protected amino group with N-subsfimted 3,4-fullero pyrrolidine.

Full Text Available Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium that can use inorganic compounds such as nitrate or ammonium as nitrogen sources. In the absence of combined nitrogen, it can fix N2 in differentiated cells called heterocysts. Anabaena also shows substantial activities of aminoacid uptake, and three ABC-type transporters for aminoacids have been previously characterized. Seven new loci encoding predicted aminoacid transporters were identified in the Anabaena genomic sequence and inactivated. Two of them were involved in aminoacid uptake. Locus alr2535-alr2541 encodes the elements of a hydrophobic aminoacid ABC-type transporter that is mainly involved in the uptake of glycine. ORF all0342 encodes a putative transporter from the dicarboxylate/aminoacid:cation symporter (DAACS family whose inactivation resulted in an increased uptake of a broad range of aminoacids. An assay to study aminoacid release from Anabaena filaments to the external medium was set up. Net release of the alanine analogue α-aminoisobutyric acid (AIB was observed when transport system N-I (a hydrophobic aminoacid ABC-type transporter was engaged in the uptake of a specific substrate. The rate of AIB release was directly proportional to the intracellular AIB concentration, suggesting leakage from the cells by diffusion.

Photoisomerizable aminoacids provide a direct avenue to the experimental manipulation of bioactive polypeptides, potentially allowing real-time, remote control of biological systems and enabling useful applications in nanobiotechnology. Herein, we report a new class of photoisomerizable aminoacids intended to cause pronounced expansion and contraction in the polypeptide backbone, i.e., to be photoelastic. These compounds, termed Abc aminoacids, employ a photoisomerizable azobiphenyl chromophore to control the relative disposition of aminomethyl and carboxyl substituents. Molecular modeling of nine Abc isomers led to the identification of one with particularly attractive properties, including the ability to induce contractions up to 13A in the backbone upon transa?cis photoisomerization. This isomer, designated mpAbc, has substituents at meta and para positions on the inner (azo-linked) and outer rings, respectively. An efficient synthesis of Fmoc-protected mpAbc was executed in which the biaryl components were formed via Suzuki couplings and the azo linkage was formed via amine/nitroso condensation; protected forms of three other Abc isomers were prepared similarly. A decapeptide incorporating mpAbc was synthesized by conventional solid-phase methods and displayed characteristic azobenzene photochemical behavior with optimal conversion to the cis isomer at 360 nm and a thermal cisa?trans half life of 100 min. at 80 AoC.

Gas-phase acidities (GA or ΔGacid) for the two most acidic common aminoacids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage’s importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3–4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two aminoacids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

Full Text Available Free aminoacid and free D-aminoacid contents of milk samples with different microorganism numbers and composition of dairy products produced from them were examined. Total microorganism number of milk samples examined varied from 1.25x106 to 2.95x106. It was established that concentration of both free D-aminoacids and free L-aminoacids increased with an increase in microorganism number. However, increase in D-aminoacid contents was higher considering its proportion. There was a particularly significant growth in the microorganism number range from 1.5x106 to 2.9x106. Based on analysis of curds and cheese samples produced using different technologies we have come to the conclusion that for fresh dairy products and for those matured over a short time there was a close relation between total microorganism number and free D-aminoacid and free L-aminoacid contents. At the same time it was found that the ratio of the enantiomers was not affected by the total microorganism number. For dairy products, however, where aminoacid production capability of the microbial cultures considerably exceeds, production of microorganisms originally present in the milk raw material, free aminoacid contents of the milk product (both D- and L-enantiomers seem to be independent of the composition of milk raw material.

Aminoacid deprivation activates the aminoacid response (AAR) pathway that enhances transcription of genes containing an aminoacid response element (AARE). The present data reveal a quantitative difference in the response to deprivation of individual aminoacids. The AAR leads to increased eukaryotic initiation factor 2α (eIF2α) phosphorylation and ATF4 translation. When HepG2 cells were deprived of an individual essential aminoacid, p-eIF2α and activating transcription factor 4 were increased, but the correlation was relatively weak. Complete aminoacid starvation in either Earle’s balanced salt solution or Krebs–Ringer bicarbonate buffer (KRB) resulted in activation of transcription driven by a SNAT2 genomic fragment that contained an AARE. However, for the KRB, a proportion of the transcription was AARE-independent suggesting that aminoacid-independent mechanisms were responsible. Therefore, activation of AARE-driven transcription is triggered by a deficiency in any one of the essential aminoacids, but the response is not uniform. Furthermore, caution must be exercised when using a medium completely devoid of aminoacids. PMID:19009228

The aliphatic aminoacids glycine, valine, leucine, and isoleucine are thermally placed into the gas phase and expanded into a vacuum system for access by time of flight mass spectroscopy and infrared (IR) spectroscopy in the energy range of 2500-4000 cm(-1) (CH, NH, OH, and stretching vibrations). The isolated neutral aminoacids are ionized by a single photon of 10.5 eV energy (118 nm), which exceeds by less than 2 eV their reported ionization thresholds. As has been reported for many hydrogen bonded acid-base systems (e.g., water, ammonia, alcohol, acid clusters, and acid molecules), the aminoacids undergo a structural rearrangement in the ion state (e.g., in simplest form, a proton transfer) that imparts sufficient excess vibrational energy to the ion to completely fragment it. No parent ions are observed. If the neutral ground state aminoacids are exposed to IR radiation prior to ionization, an IR spectrum of the individual isomers for each aminoacid can be determined by observation of the ion intensity of the different fragment mass channels. Both the IR spectrum and fragmentation patterns for individual isomers can be qualitatively identified and related to a particular isomer in each instance. Thus, each fragment ion detected presents an IR spectrum of its particular parent aminoacid isomer. In some instances, the absorption of IR radiation by the neutral aminoacid parent isomer increases a particular fragmentation mass channel intensity, while other fragmentation mass channel intensities decrease. This phenomenon can be rationalized by considering that with added energy in the molecule, the fragmentation channel populations can be modulated by the added vibrational energy in the rearranged ions. This observation also suggests that the IR absorption does not induce isomerization in the ground electronic state of these aminoacids. These data are consistent with theoretical predictions for isolated aminoacid secondary structures and can be related to

Aryl-keto-containing α-aminoacids are of great importance in organic chemistry and biochemistry. They are valuable intermediates for the construction of hydroxyl α-aminoacids, nonproteinogenic α-aminoacids, as well as other biofunctional components. Friedel-Crafts acylation is an effective method to prepare aryl-keto derivatives. In this review, we summarize the preparation of aryl-keto containing α-aminoacids by Friedel-Crafts acylation using acidic α-aminoacids as acyl-donors and Lewis acids or Brönsted acids as catalysts.

In order to disclose the dominant interfacial interaction between aminoacids and ordered mesoporous materials, the adsorption behaviors of five aminoacids on four mesoporous materials were investigated in aqueous solutions with adjustable aminoacid concentration, ion strength, and pH. The selected aminoacids were acidicaminoacid glutamic acid (Glu), basic aminoacid arginine (Arg), and neutral aminoacids phenylalanine (Phe), leucine (Leu), and alanine (Ala), and the selected mesoporous materials were SBA-15, Al-SBA-15, CH3(10%)-SBA-15, and CH3(20%)-SBA-15. The adsorption capacities of Glu and Arg were strongly dependent on pH and surface charge of the mesoporous adsorbent. The adsorption of Phe showed pH insensitivity but depended on the surface organic functionalization of mesoporous adsorbent. On the basis of the theoretical analysis about the interaction between aminoacid and adsorbent, such a remarkable difference was attributed to the different nature of the interaction between aminoacid and adsorbent. Arg could be readily adsorbed on the surface of SBA-15, especially Al-SBA-15, under appropriate pH in which the electrostatic interaction was predominant. The driving force of Phe adsorption on mesoporous adsorbent mainly came from the hydrophobic interaction. Therefore, the adsorption capability of Arg decreased with increasing ion strength of solution, while the adsorption capability of Phe increased with the increasing degree of CH3 functionalization on SBA-15. For neutral aminoacid Phe, Ala, and Leu, the adsorption capability increased with the increase of the length of their side chains, which was another evidence of hydrophobic effect. Thus, all the adsorption of aminoacids on mesoporous silica materials can be decided by the combined influence of two fundamental interactions: electrostatic attraction and hydrophobic effect.

A method for aminoacid sequence and D/L configuration identification of peptides by using fluorogenic Edman reagent 7-[(N, N-dimethylamino)sulfonyl]-2,1,3-benzoxadiazol-4-yl isothiocyanate (DBD-NCS) has been developed. This method was based on the Edman degradation principle with some modifications. A peptide or protein was coupled with DBD-NCS under basic conditions and then cyclized/cleaved to produce DBD-thiazolinone (TZ) derivative by BF3, a Lewis acid, which could significantly suppress the aminoacid racemization. The liberated DBD-TZ aminoacid was hydrolyzed to DBD-thiocarbamoyl (TC) aminoacid under a weakly acidic condition and then oxidized by NaNO2/H+ to DBD-carbamoyl (CA) aminoacid which was a stable and had a strong fluorescence intensity. The individual DBD-CA aminoacids were separated on a reversed-phase high-performance liquid chromatography (RP-HPLC) for aminoacid sequencing and their enantiomers were resolved on a chiral stationary-phase HPLC for identifying their D/L configurations. Combination of the two HPLC systems, the aminoacid sequence and D/L configuration of peptides could be determined. This method will be useful for searching D-amino-acid-containing peptides in animals.

Gold nanoparticles (4-7nm) were synthesized from tetraauric acid using various aminoacids as reducing and capping agents. The gold nanoparticles were produced from the incubation of a AuCl4(-) solution with an aminoacid at 80°C for 20min. Among the twenty aminoacids tested, several aminoacids produced gold nanoparticles. The color of the nanoparticle solutions varied with the aminoacids used for the reduction. We adopted l-histidine as a reducing agent and investigated the effects of the synthesis conditions on the gold nanoparticles. The His and AuCl4(-) concentrations affected the size of the gold nanoparticles and their aggregates. The pH of the reaction solution also affected the reaction yields and the shape of the gold nanoparticles.

Affinity membranes for the treatment of solutions containing aminoacids were obtained via lithiating polysulfone that was subsequently converted with glycidylether. From this polymer asymmetric ultrafiltration membranes were cast. The membranes were reacted with iminodiacetic acid yielding membranes fitted out with bidentate chelates. The same reaction path was applied to commercially available symmetric microfiltration membranes. The chelate-bearing membranes were complexed with Cu, Ni, and Zn ions. For the experiments with aminoacids only the Cu-complexed membranes were used. The complexation constants for histidine and tryptophan for six different membranes were determined. Because of the affinity of these two aminoacids for the complexed Cu ions, they could easily be separated from solutions containing aminoacids such as alanine, glycine, and valine. Also, concentrating very dilute aminoacid solutions was carried out successfully.

Numerous studies were carried out about aminoacidic composition of vegetable proteins, but information about the free aminoacid pool and the role of these substances is very incomplete. The aim of this paper was to contribute to the scarce knowledge concerning the composition of free aminoacids in botanicals and botanical preparations widely used as food, in dietary supplements, and in pharmaceutical products. This work studied the composition of free aminoacids, identified the major components of 19 species of plants, and evaluated the influence of different types of extraction on the aminoacid profile. Aminoacids were determined using an automatic precolumn derivatization with fluorenylmethyl-chloroformate and reversed-phase liquid chromatography with fluorescence and ultraviolet detection. The amounts of total free aminoacids varied widely between plants, from approximately 12 g in 100 g of Echinacea pallida extract to less than 60 mg in the same amount of Coleus forskohlii, Garcinia cambogia, and Glycine max. In 13 plants arginine, asparagine, glutamine, proline, and gamma-aminobutyric acid were the free aminoacids found in preponderant quantities. The levels of free aminoacids above the quantification limit in 36 assayed samples of botanicals, extracts, and supplements are shown.

Incorporation of unnatural aminoacids with unique chemical functionalities has proven to be a valuable tool for expansion of the functional repertoire and properties of proteins as well as for structure-function analysis. Incorporation of alpha-hydroxy acids (primary amino group is substituted with hydroxyl) leads to the synthesis of proteins with peptide bonds being substituted by ester bonds. Practical application of this modification is limited by the necessity to prepare corresponding acylated tRNA by chemical synthesis. We investigated the possibility of enzymatic incorporation of alpha-hydroxy acid and acid analogues (lacking amino group) of aminoacids into tRNA using aminoacyl-tRNA synthetases (aaRSs). We studied direct acylation of tRNAs by alpha-hydroxy acid and acid analogues of aminoacids and corresponding chemically synthesized analogues of aminoacyl-adenylates. Using adenylate analogues we were able to enzymatically acylate tRNA with aminoacid analogues which were otherwise completely inactive in direct aminoacylation reaction, thus bypassing the natural mechanisms ensuring the selectivity of tRNA aminoacylation. Our results are the first demonstration that the use of synthetic aminoacyl-adenylates as substrates in tRNA aminoacylation reaction may provide a way for incorporation of unnatural aminoacids into tRNA, and consequently into proteins.

Gas-phase acidities (GA or [Delta]Gacid) for the two most acidic common aminoacids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage's importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3-4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two aminoacids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

The radioactive aminoacid's synthesized from C{sup 14}O{sub 2} by green algae both in the light and in the dark after CO{sub 2}-free preillumination have been separated and identified using paper chromatography and radioautography. The radioactive aminoacids identified were aspartic acid, alanine and smaller amounts of 3- and 4-carbon aminoacids. This finding as well as the total absence of radioactive glutamic acid substantiates the mechanism for reduction of CO{sub 2} previously postulated by members of this laboratory.

Sets of aminoacids containing sufficient trifunctional monomer are thermally polymerized at temperatures such as 65 deg; the aminoacids order themselves. Various polymers have diverse catalytic activities. The polymers aggregate, in aqueous solution, to cell-like structures having those activities plus emergent properties, e.g. proliferatability. Polyamino acids containing sufficient lysine catalyze conversion of free aminoacids, by ATP, to small peptides and a high molecular weight fraction. The lysine-rich proteinoid is active in solution, within suspensions of cell-like particles, or in other particles composed of lysine-rich proteinoid and homopolyribonucleotide. Selectivities are observed. An archaic polyamino acid prelude to coded protein synthesis is indicated.

Signaling through the mammalian target of rapamycin (mTOR) in response to aminoacid availability controls many cellular and developmental processes. mTOR is a master regulator of myogenic differentiation, but the pathways mediating aminoacid signals in this process are not known. Here we examine the Rag GTPases and the class III phosphoinositide 3-kinase (PI3K) Vps34, two mediators of aminoacid signals upstream of mTOR complex 1 (mTORC1) in cell growth regulation, for their potential involvement in myogenesis. We find that, although both Rag and Vps34 mediate aminoacid activation of mTORC1 in C2C12 myoblasts, they have opposing functions in myogenic differentiation. Knockdown of RagA/B enhances, whereas overexpression of active RagB/C mutants impairs, differentiation, and this inhibitory function of Rag is mediated by mTORC1 suppression of the IRS1-PI3K-Akt pathway. On the other hand, Vps34 is required for myogenic differentiation. Aminoacids activate a Vps34-phospholipase D1 (PLD1) pathway that controls the production of insulin-like growth factor II, an autocrine inducer of differentiation, through the Igf2 muscle enhancer. The product of PLD, phosphatidic acid, activates the enhancer in a rapamycin-sensitive but mTOR kinase-independent manner. Our results uncover aminoacid-sensing mechanisms controlling the homeostasis of myogenesis and underline the versatility and context dependence of mTOR signaling.

The aminoacid contents of edible insects from different provinces of Mexico and reference proteins were analysed by reversed-phase high-performance liquid chromatography and ion exchange chromatography. The insect aminoacid contents were higher than the adult requirements indicated by the WHO/FAO pattern.

Ileal recovery of endogenous aminoacids is important for determining balanced homeostasis of protein metabolism in pigs and the true digestibility of dietary protein. In this context, the ileal recoveries of endogenous aminoacids were determined in growing pigs fed guanidinated Nutrisoy protein

Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto aminoacids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto aminoacids using these orthogonal pairs.

Aminoacid permeases (AAPs) in the plasma membrane (PM) of Saccharomyces cerevisiae are responsible for the uptake of aminoacids and involved in regulation of their cellular levels. Here, we report on a strong and complex module for PM association found in the C-terminal tail of AAPs. Using in sili

Aminoacids represent a class of versatile chiral building blocks for a whole range of fine chemicals, used in the pharmaceutical and agro-chemical industry. Considerable experience currently is available with a wide variety of chemo-enzymatic processes for the synthesis of aminoacids, which is app

For the process of milk production, the dairy cow requires nutrients of which energy supplying nutrients and protein or aminoacid supplying nutrients are the most important. Aminoacid supplying nutrients have to be absorbed from the small intestine and the research reported in this thesis mainly c

Full Text Available Discussions are made concerning realistic mechanisms for the origin of L-aminoacids in the biosphere. As the most plausible mechanism, it is proposed that a mixture of racemic aminoacids in the prebiotic sea caused spontaneous and effective optical resolution through self crystallization, even if asymmetric synthesis of a single aminoacid has never occurred without the aid of an optically active molecule. This hypothesis is based on recrystallization of a mixture of D,L-aminoacids in the presence of excess of D,L-asparagine (Asn. The enantiomeric excess (ee of each aminoacid in the resulting crystals indicates that crystallization of co-existing aminoacids with the configuration same as that of Asn took place, although it was incidental whether the enrichment occurred in L- or D-aminoacids. In addition, the resulting ee was sufficiently high (up to 100% to account for the predominance of L-aminoacids on the earth.

For the process of milk production, the dairy cow requires nutrients of which energy supplying nutrients and protein or aminoacid supplying nutrients are the most important. Aminoacid supplying nutrients have to be absorbed from the small intestine and the research reported in this thesis mainly

A diverse range of natural compounds interfere with the synthesis and other aspects of aminoacid metabolism. Some are aminoacid analogues, but most are not. This review covers a number of specific natural phytotoxic compounds by molecular target site. Inhibition of glutamine synthetase is of part...

-sequence information, using machine learning strategies, where the primary goal is the discovery of novel powerful representations for use in AI techniques. In the case of proteins and the 20 different aminoacids they typically contain, it is also a secondary goal to discover how the current selection of aminoacids...

Aminoacid permeases (AAPs) in the plasma membrane (PM) of Saccharomyces cerevisiae are responsible for the uptake of aminoacids and involved in regulation of their cellular levels. Here, we report on a strong and complex module for PM association found in the C-terminal tail of AAPs. Using in

Full Text Available A model is described that can be used to estimate the bulk polarization of largerotating meteoroids in the magnetic field of a neutron star. The results of this model areapplicable to the Supernova Neutrino AminoAcid Processing model, which describes onepossible way in which the aminoacids, known in nearly all cases to exhibit supramolecularchirality, could have become enantiomeric.

Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto aminoacids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto aminoacids using these orthogonal pairs.

Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto aminoacids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto aminoacids using these orthogonal pairs.

Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto aminoacids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto aminoacids using these orthogonal pairs.

Recent years have witnessed the discovery that aminoacids (AA) are not only cell signaling molecules but are also regulators of gene expression and the protein phosphorylation cascade. Additionally, AA are key precursors for syntheses of hormones and low-molecular weight nitrogenous substances with each having enormous biological importance. Physiological concentrations of AA and their metabolites (e.g., nitric oxide, polyamines, glutathione, taurine, thyroid hormones, and serotonin) are required for the functions. However, elevated levels of AA and their products (e.g., ammonia, homocysteine, and asymmetric dimethylarginine) are pathogenic factors for neurological disorders, oxidative stress, and cardiovascular disease. Thus, an optimal balance among AA in the diet and circulation is crucial for whole body homeostasis. There is growing recognition that besides their role as building blocks of proteins and polypeptides, some AA regulate key metabolic pathways that are necessary for maintenance, growth, reproduction, and immunity. They are called functional AA, which include arginine, cysteine, glutamine, leucine, proline, and tryptophan. Dietary supplementation with one or a mixture of these AA may be beneficial for (1) ameliorating health problems at various stages of the life cycle (e.g., fetal growth restriction, neonatal morbidity and mortality, weaning-associated intestinal dysfunction and wasting syndrome, obesity, diabetes, cardiovascular disease, the metabolic syndrome, and infertility); (2) optimizing efficiency of metabolic transformations to enhance muscle growth, milk production, egg and meat quality and athletic performance, while preventing excess fat deposition and reducing adiposity. Thus, AA have important functions in both nutrition and health.

Myriad scientific domains concern themselves with biological electron transfer (ET) events that span across vast scales of rate and efficiency through a remarkably fine-tuned integration of aminoacid (AA) sequences, electronic structure, dynamics, and environment interactions. Within this intricate scheme, many questions persist as to how proteins modulate electron-tunneling properties. To help elucidate these principles, we develop a model set of peptides representing the common α-helix and β-strand motifs including all natural AAs within implicit protein-environment solvation. Using an effective Hamiltonian strategy with density functional theory, we characterize the electronic coupling through these peptides, furthermore considering side-chain dynamics. For both motifs, predictions consistently show that backbone-mediated electronic coupling is distinctly sensitive to AA type (aliphatic, polar, aromatic, negatively charged and positively charged), and to side-chain orientation. The unique properties of these residues may be employed to design activated, deactivated, or switch-like superexchange pathways. Electronic structure calculations and Green’s function analyses indicate that localized shifts in the electron density along the peptide play a role in modulating these pathways, and further substantiate the experimentally observed behavior of proline residues as superbridges. The distinct sensitivities of tunneling pathways to sequence and conformation revealed in this electronic coupling database help improve our fundamental understanding of the broad diversity of ET reactivity and provide guiding principles for peptide design.

The recent years have witnessed growing interest in biochemistry, physiology and nutrition of aminoacids (AA) in growth, health and disease of humans and other animals. This results from the discoveries of AA in cell signaling involving protein kinases, G protein-coupled receptors, and gaseous molecules (i.e., NO, CO and H2S). In addition, nutritional studies have shown that dietary supplementation with several AA (e.g., arginine, glutamine, glutamate, leucine, and proline) modulates gene expression, enhances growth of the small intestine and skeletal muscle, or reduces excessive body fat. These seminal findings led to the new concept of functional AA, which are defined as those AA that participate in and regulate key metabolic pathways to improve health, survival, growth, development, lactation, and reproduction of the organisms. Functional AA hold great promise in prevention and treatment of metabolic diseases (e.g., obesity, diabetes, and cardiovascular disorders), intrauterine growth restriction, infertility, intestinal and neurological dysfunction, and infectious disease (including viral infections).

There has long been a debate as to whether rock varnish deposits are microbially mediated or are deposited by inorganic processes. Varnished rocks are found throughout the world primarily in arid and semi-arid regions. The varnish coats are typically up to 200 microns thick and are composed of clays and alternating layers enriched in manganese and iron oxides. The individual layers range in thickness from 1 micron to greater than 10 microns and may continue laterally for more than a 100 microns. Overlapping botryoidal structures are visible in thin section and scanning electron micrographs. The coatings also include small amounts of organic mater and detrital grains. Amino-acid hydrolysates offer a means of assessing the organic composition of rock varnish collected from the Sonoran Desert, near Phoenix, AZ. Chromatographic analyses of hydrolysates from powdered samples of rock varnish suggest that the interior of rock varnish is relatively enriched in aminoacids and specifically in d-alanine and glutamic acid. Peptidoglycan (murein) is the main structural component of gram-positive bacterial cell walls. The d-enantiomer of alanine and glutamic acid are specific to peptidoglycan and are consequently an indicator for the presence of bacteria. D-alanine is also found in teichoic acid which is only found in gram-positive bacteria. Several researchers have cultured bacteria from the surface of rock varnish and most have been gram-positive, suggesting that gram-positive bacteria are intimately associated with varnish coatings and may play a role in the formation of varnish coatings.

A semiempirical molecular orbital method is used to characterize the binding of aminoacids to hexahydrated Cu(2+) and Ni(2+), a process presumed to occur when they are adsorbed in the interlamellar space of homoionic smectite clays. Five alpha-aminoacids, beta-alanine, and gamma-aminobutyric acid were used to investigate the metal ion and aminoacid specificity in binding. It was assumed that the alpha, beta, and gamma-aminoacids would bind as bidentate anionic ligands, forming either 1:1 or 1:2 six-coordinated five, six, and seven-membered-ring chelate complexes, respectively. Energies of complex formation, optimized geometries, and electron and spin distribution were determined; and steric constraints of binding of the aminoacids to the ion-exchanged cations in the interlamellar spacing of a clay were examined. Results indicate that hexahydrated Cu(2+) forms more stable complexes than hexahydrated Ni(2+) with all the aminoacids studied. However, among these aminoacids, complex formation does not favor the adsorption of the biological subset. Calculated energetics of complex formation and steric constraints are shown to predict that 1:1 rather than 1:2 metal-aminoacid complexes are generally favored in the clay.

A semiempirical molecular orbital method is used to characterize the binding of aminoacids to hexahydrated Cu(2+) and Ni(2+), a process presumed to occur when they are adsorbed in the interlamellar space of homoionic smectite clays. Five alpha-aminoacids, beta-alanine, and gamma-aminobutyric acid were used to investigate the metal ion and aminoacid specificity in binding. It was assumed that the alpha, beta, and gamma-aminoacids would bind as bidentate anionic ligands, forming either 1:1 or 1:2 six-coordinated five, six, and seven-membered-ring chelate complexes, respectively. Energies of complex formation, optimized geometries, and electron and spin distribution were determined; and steric constraints of binding of the aminoacids to the ion-exchanged cations in the interlamellar spacing of a clay were examined. Results indicate that hexahydrated Cu(2+) forms more stable complexes than hexahydrated Ni(2+) with all the aminoacids studied. However, among these aminoacids, complex formation does not favor the adsorption of the biological subset. Calculated energetics of complex formation and steric constraints are shown to predict that 1:1 rather than 1:2 metal-aminoacid complexes are generally favored in the clay.

The discovery of the relationship between aminoacids is important in terms of the replacement ability, as used in protein engineering homology studies, and gaining a better understanding of the roles which various properties of the residues play in the creation of a unique, stable, 3-D protein structure. Aminoacid sequences of proteins edited by evolution are anything but random. The measure of nonrandomness, i.e. the level of editing, can be characterized by an independence divergence value. This parameter is used to generate binary tree relationships between aminoacids. The relationships of residues presented in this paper are based on protein building features and not on the physico-chemical characteristics of aminoacids. This approach is not biased by the tautology present in all sequence similarity-based relationship studies. The roles which various physico-chemical characteristics play in the determination of the relationships between aminoacids are also discussed.

Full Text Available A mechanism for creating an enantioenrichment in the aminoacids, the building blocks of the proteins, that involves global selection of one handedness by interactions between the aminoacids and neutrinos from core-collapse supernovae is defined. The chiral selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the aminoacids, or in precursor molecules, which in turn couple to the molecular chirality. It also requires an asymmetric distribution of neutrinos emitted from the supernova. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting aminoacids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth’s proteinaceous amino acids.

Full Text Available Autotrophic microalgae are a promising bioproducts platform. However, the fundamental requirements these organisms have for nitrogen fertilizer severely limit the impact and scale of their cultivation. As an alternative to inorganic fertilizers, we investigated the possibility of using aminoacids from deconstructed biomass as a nitrogen source in the genus Dunaliella. We found that only four aminoacids (glutamine, histidine, cysteine, and tryptophan rescue Dunaliella spp. growth in nitrogen depleted media, and that supplementation of these aminoacids altered the metabolic profile of Dunaliella cells. Our investigations revealed that histidine is transported across the cell membrane, and that glutamine and cysteine are not transported. Rather, glutamine, cysteine, and tryptophan are degraded in solution by a set of oxidative chemical reactions, releasing ammonium that in turn supports growth. Utilization of biomass-derived aminoacids is therefore not a suitable option unless additional aminoacid nitrogen uptake is enabled through genetic modifications of these algae.

Aminoacid composition was analyzed in the glycine-rich repeat region of 306 collagens belonging to three major families of collagens from both parasitic and free-living nematodes. The collagens of parasitic species showed a tendency toward decreased usage of the hydrophilic residues A, D, and Q and increased usage of the hydrophobic resides I, L, and M; and this trend was seen in parasitic species of both the order Rhabdita and the order Spirurida. The aminoacid composition of collagens of parasitic Rhabdita thus tended to resemble those of Spirurida more than that of free-living Rhabdita, suggesting an association between aminoacid composition and a parasitic lifestyle. Computer predictions suggested that the more hydrophobic aminoacid composition was associated with a reduction of the propensity towards B-cell epitope formation, suggesting that evasion of host immune responses may be a major selective factor responsible for the parasite-specific trend in collagen aminoacid composition.

The spatial distribution of total hydrolysable aminoacids (THAA) and aminoacid enantiomers (D- and L-forms) was investigated in sediments underlying two contrasting Chilean upwelling regions,: at ~23°S off Antofagasta and at ~36°S off Concepcion. The contribution of aminoacids to total organic...... carbon (%TAAC: 7-14%) and total nitrogen (%TAAN: 23-38%) in surface sediments decreased with increasing water depth (from 126 to 1350 m) indicating that organic matter becomes increasingly decomposed in surface sediments at greater water depth. Changes in the ratio between the protein aminoacid...... aspartate and its non-protein degradation product β-alanine confirmed this observation. Furthermore, estimates of THAA mineralization showed that sedimentary aminoacid reactivity decreased with both increasing water depth as well as progressive degradation status of the organic matter that was incorporated...

Full Text Available Aminoacids are the building blocks of proteins and are considered as the key precursors for the formation of hormones and low molecular weight nitrogenous substances with biological importance. Since the analysis of aminoacids has been carried out for both qualitative and quantitative purposes with an aim to study their levels in the plasma concentration, the quantitative determination, in particular, also helps in the diagnosis of different diseases associated with their deficiency. This review article deals with the determination of aminoacids by chromatographic methods which include ion-exchange chromatography (IEC, high performance liquid chromatography (HPLC, reverse phase-high performance liquid chromatography (RP-HPLC and ultra-performance liquid chromatography (UPLC. The review will also give an idea for the preparation of samples, derivatization methods for the analysis of aminoacids (direct and indirect methods and separation of aminoacids by high performance liquid chromatographic technique.

A mechanism for creating enantiomerism in the aminoacids, the building blocks of the proteins, that involves global selection of one chirality by interactions between the aminoacids and neutrinos from core-collapse supernovae is described. The selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the aminoacids, or in precursor molecules, which in turn couple to the molecular chirality. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting aminoacids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth's aminoacids.

A mechanism for creating an enantioenrichment in the aminoacids, the building blocks of the proteins, that involves global selection of one handedness by interactions between the aminoacids and neutrinos from core-collapse supernovae is described. The chiral selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the aminoacids, or in precursor molecules, which in turn couple to the molecular chirality. It also requires an asymmetric distribution of neutrinos emitted from the supernova. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting aminoacids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth's proteinaceous aminoacids.

Gut homeostasis plays a major role in health and may be regulated by quantitative and qualitative food intake. In the intestinal mucosa, an intense renewal of proteins occurs, at approximately 50% per day in humans. In some pathophysiological conditions, protein turnover is altered and may contribute to intestinal or systemic diseases. Aminoacids are key effectors of gut protein turnover, both as constituents of proteins and as regulatory molecules limiting intestinal injury and maintaining intestinal functions. Many studies have focused on two aminoacids: glutamine, known as the preferential substrate of rapidly dividing cells, and arginine, another conditionally essential aminoacid. The effects of glutamine and arginine on protein synthesis appear to be model and condition dependent, as are the involved signaling pathways. The regulation of gut protein degradation by aminoacids has been minimally documented until now. This review will examine recent data, helping to better understand how aminoacids regulate intestinal protein metabolism, and will explore perspectives for future studies.

The integrated stress response (ISR) is a homeostatic mechanism by which eukaryotic cells sense and respond to stress-inducing signals, such as aminoacid starvation. General controlled non-repressed (GCN2) kinase is a key orchestrator of the ISR, and modulates protein synthesis in response to aminoacid starvation. Here we demonstrate in mice that GCN2 controls intestinal inflammation by suppressing inflammasome activation. Enhanced activation of ISR was observed in intestinal antigen presenting cells (APCs) and epithelial cells during aminoacid starvation, or intestinal inflammation. Genetic deletion of Gcn2 (also known as Eif2ka4) in CD11c(+) APCs or intestinal epithelial cells resulted in enhanced intestinal inflammation and T helper 17 cell (TH17) responses, owing to enhanced inflammasome activation and interleukin (IL)-1β production. This was caused by reduced autophagy in Gcn2(-/-) intestinal APCs and epithelial cells, leading to increased reactive oxygen species (ROS), a potent activator of inflammasomes. Thus, conditional ablation of Atg5 or Atg7 in intestinal APCs resulted in enhanced ROS and TH17 responses. Furthermore, in vivo blockade of ROS and IL-1β resulted in inhibition of TH17 responses and reduced inflammation in Gcn2(-/-) mice. Importantly, acute aminoacid starvation suppressed intestinal inflammation via a mechanism dependent on GCN2. These results reveal a mechanism that couples aminoacid sensing with control of intestinal inflammation via GCN2.

Full Text Available There are large varieties of oil seeds and legumes in India, which are part of traditional food system but whose nutritional and economic values have not been completely determine and are far less exploited for both human and livestock utilization. The objective of this study was to evaluate Sunflower (Helianths annuus LSF-11, Sunflower (Helianths annuus LSF-8, Safflower (Carthamus tinctorius PBNS-12, Safflower (Carthamus tinctorius PBNS-40, and Ground nut (Arachis hypogaea JL-24 seeds with the aim of qualifying and quantifying chemical information that might serve as a guide to exploit its potentials and benefits for human and animal nutrition. The aminoacid profile of these oil seed were carried out using standard methods. Aminoacid analysis using technical sequential multisampling aminoacid analyzer detected all essential and non essential aminoacids. The seeds are rich in four aminoacids (EAA and NEAA (g/16g N Glutamic acid (5.083, Aspartic acid (3.459, Proline (6.412 and Methionine (3.001%, respectively. The other aminoacids compared well with the FAO reference protein, Serine appeared to be the most limiting aminoacid percent. Based on results of this study, the lesser known and under-utilized oil seeds, they can be a potential source and energy supplements in livestock feed.

Full Text Available Our objective was to measure maternal plasma and amniotic fluid aminoacid concentrations in pregnant women diagnosed as having fetuses with gastroschisis in the second trimester of pregnancy. Twenty-one pregnant women who had fetuses with gastroschisis detected by ultrasonography (gastroschisis group in the second trimester and 32 women who had abnormal triple screenings indicating an increased risk for Down syndrome but had healthy fetuses (control group were enrolled in the study. Amniotic fluid was obtained by amniocentesis, and maternal plasma samples were taken simultaneously. The chromosomal analysis of the study and control groups was normal. Levels of free aminoacids and non-essential aminoacids were measured in plasma and amniotic fluid samples using EZ:fast kits (EZ:fast GC/FID free (physiological aminoacid kit by gas chromatography (Focus GC AI 3000 Thermo Finnigan analyzer. The mean levels of essential aminoacids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine and non-essential aminoacids (alanine, glycine, proline, and tyrosine in amniotic fluid were found to be significantly higher in fetuses with gastroschisis than in the control group (P < 0.05. A significant positive correlation between maternal plasma and amniotic fluid concentrations of essential and nonessential aminoacids was found only in the gastroschisis group (P < 0.05. The detection of significantly higher aminoacid concentrations in the amniotic fluid of fetuses with a gastroschisis defect than in healthy fetuses suggests the occurrence of aminoacid malabsorption or of aminoacid leakage from the fetus into amniotic fluid.

The hydration of selected aminoacids, alanine, glycine, proline, valine, isoleucine and phenylalanine, has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in H2O. The difference spectra procedure and the chemometric method have been applied to remove the contribution of bulk water and thus to separate the spectra of solute-affected HDO. To support interpretation of obtained spectral results, molecular dynamics simulations of aminoacids were performed. The structural-energetic characteristic of these solute-affected water molecules shows that, on average, water affected by aminoacids forms stronger and shorter H-bonds than those in pure water. Differences in the influence of aminoacids on water structure have been noticed. The effect of the hydrophobic side chain of an aminoacid on the solvent interactions seems to be enhanced because of the specific cooperative coupling of water strong H-bond chain, connecting the carboxyl and amino groups, with the clathrate-like H-bond network surrounding the hydrocarbon side chain. The parameter derived from the spectral data, which corresponds to the contributions of the population of weak hydrogen bonds of water molecules which have been substituted by the stronger ones in the hydration sphere of aminoacids, correlated well with the aminoacid hydrophobicity indexes.

Fatty acidaminoacid conjugates (FACs) have been found in noctuid as well as sphingid caterpillar oral secretions; in particular, volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and its biochemical precursor, N-linolenoyl-L-glutamine, are known elicitors of induced volatile emissions in corn plants. These induced volatiles, in turn, attract natural enemies of the caterpillars. In a previous study, we showed that N-linolenoyl-L-glutamine in larval Spodoptera litura plays an important role in nitrogen assimilation which might be an explanation for caterpillars synthesizing FACs despite an increased risk of attracting natural enemies. However, the presence of FACs in lepidopteran species outside these families of agricultural interest is not well known. We conducted FAC screening of 29 lepidopteran species, and found them in 19 of these species. Thus, FACs are commonly synthesized through a broad range of lepidopteran caterpillars. Since all FAC-containing species had N-linolenoyl-L-glutamine and/or N-linoleoyl-L-glutamine in common, and the evolutionarily earliest species among them had only these two FACs, these glutamine conjugates might be the evolutionarily older FACs. Furthermore, some species had glutamic acid conjugates, and some had hydroxylated FACs. Comparing the diversity of FACs with lepidopteran phylogeny indicates that glutamic acid conjugates can be synthesized by relatively primitive species, while hydroxylation of fatty acids is limited mostly to larger and more developed macrolepidopteran species.

We measured the urine aminoacid distribution patterns before, during and after space flight on the Space Shuttle. The urine samples were collected on two separate flights of the space shuttle. The first flight lasted 9.5 days and the second flight 15 days. Urine was collected continuously on 8 subjects for the period beginning 10 d before launch to 6 d after landing. Results: In contrast to the earlier Skylab missions where a pronounced amino aciduria was found, on shuttle the urinary aminoacids showed little change with spaceflight except for a marked decrease in all of the aminoacids on FD (flight day) 1 (pvaline on FD3 and FD4 (p<0.05). Conclusions: (i) Amino aciduria is not an inevitable consequence of space flight. (ii) The occurrence of amino aciduria, like muscle protein breakdown is a mission specific effect rather than part of the general human response to microgravity.

An overview of the use of non-protein aminoacids in the design of conformationally well-defined peptides, based on work from the author’s laboratory, is discussed. The crystal structures of several designed oligopeptides illustrate the use -aminoisobutyric acid (Aib) in the construction of helices, D-aminoacids in the design of helix termination segments and DPro-Xxx segments for nucleating of -hairpin structures. - and -aminoacid residues have been used to expand the range of designed polypeptide structures.

A micelle-enhanced ultrafiltration system, which can potentially be used for large scale separations, has been used to investigate the resolution of aminoacid enantiomers. For this purpose aminoacid derivatives were synthesized, which in combination with copper(II) ions were used as chiral selecto

D-Aminoacids are stereoisomers of L-aminoacids. They are often called unnatural aminoacids, but several D-aminoacids have been found in mammalian brains. Among them, D-serine is abundant in the forebrain and functions as a co-agonist of NMDA receptors to enhance neurotransmission. D-Amino-acid oxidase (DAO), which degrades neutral and basic D-aminoacids, is mainly present in the hindbrain. DAO catabolizes D-serine and, therefore, modulates neurotransmission. In the brains of mutant mice and rats lacking DAO activity, the amounts of D-serine and other D-aminoacids are markedly increased. Mutant mice manifested behavioral changes characteristic of altered NMDA receptor activity, likely due to increased levels of D-serine. D-Serine and DAO have been demonstrated to play important roles in cerebellar development and synaptic plasticity. They have also implicated in amyotrophic lateral sclerosis and pain response. There have also been several lines of evidence correlating DAO with schizophrenia. Taken together, the experiments indicate that D-aminoacids and DAO have pivotal functions in the central nervous system.

A method was developed for quantifying 17 aminoacids in tobacco leaves by using an A300 aminoacid analyzer and chemometric resolution. In the method, aminoacids were eluted by the buffer solution on an ion-exchange column. After reacting with ninhydrin, the derivatives of aminoacids were detected by ultraviolet detection. Most aminoacids are separated by the elution program. However, five peaks of the derivatives are still overlapping. A non-negative immune algorithm was employed to extract the profiles of the derivatives from the overlapping signals, and then peak areas were adopted for quantitative analysis of the aminoacids. The method was validated by the determination of aminoacids in tobacco leaves. The relative standard deviations (n = 5) are all less than 2.54% and the recoveries of the spiked samples are in a range of 94.62-108.21%. The feasibility of the method was proved by analyzing the 17 aminoacids in 30 tobacco leaf samples.

Site-specific incorporation of noncanonical aminoacids (ncAAs) into proteins expressed in E. coli using UAG-suppression competes with termination mediated by release factor 1 (RF1). Recently, unconditional deletion of RF1 was achieved in a genomically recoded E. coli (C321), devoid of all endogenous UAG stop codons. Here we evaluate the efficiency of ncAA incorporation in this strain using optimized suppression vectors. Even though the absence of RF1 does not benefit the suppression efficiency of a single UAG codon, multi-site incorporation of a series of chemically distinct ncAAs was significantly improved.

Aminoacids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory aminoacid extraction protocol by quantitatively measuring the yields of extracted aminoacids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The aminoacids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the aminoacids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that aminoacids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Aminoacids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to aminoacid decomposition at this temperature. The optimal subcritical water extraction conditions for these aminoacids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

Full Text Available This article is the second part of a series dealing with organometallic and bioorganometallic chemistry. In the first part of this series a short review on the history and development of these disciplines was given, emphasizing the importance and scope of bioorganometallic chemistry as a new field dealing with conjugates of organometallics and biomolecules (DNA, PNA, aminoacids, peptides.... From the variety of biorganometallics, syntheses and properties of simple conjugates of ferrocene with natural aminoacids/peptides were elaborated inter alia. This material is the basis for the second part in which ferrocene aminoacids are described. The introduction presents nonproteinogenic alicyclic and aromatic aminoacids as the models for the title compounds. Naturally occurring aminoacids labelled with ferrocene moiety mostly retain properties of the biomolecules included. Contrary to these ω-ferrocenylamino acids, one could imagine specific aminoacids with inserted ferrocene core belonging to either homo- or heterodisubstituted type. The central part of this article is devoted to our investigations of the second type - H2N-(CH2m-Fn-(CH2n-COOH. The general rational procedure for synthesis of these compounds and of their N- and/or C-protected derivatives via the azide intermediates N3-CO-(CH2m- Fn-(CH2n-COOMe has been described. In the solid state derivatives of ferrocene aminoacids contain intermolecular hydrogen bonds giving dimeric structures, three-dimensional networks or endless helical chains. The solutions of homologues Ac-NH-(CH2m-Fn-(CH2n-COOMe in nonpolar solvents are dominated by open form conformers. Compounds containing 2–3 ferrocene cores connected by amide, imide and oxalamide spacers were prepared by oligomerization of 1'-aminoferrocene-1-carboxylic acid (Fca or by its condensation with the appropriate reagents. Similar to natural aminoacids, ferrocene aminoacids are water-soluble substances with high melting points

Aminoacids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory aminoacid extraction protocol by quantitatively measuring the yields of extracted aminoacids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The aminoacids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the aminoacids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that aminoacids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Aminoacids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to aminoacid decomposition at this temperature. The optimal subcritical water extraction conditions for these aminoacids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

Full Text Available Many methods to estimate aminoacid requirement based on aminoacid profile of fish have been proposed. This study evaluates the methodology proposed by Meyer & Fracalossi (2005 and by Tacon (1989 to estimate aminoacids requirement of fish, which do exempt knowledge on previous nutritional requirement of reference aminoacid. Data on aminoacid requirement of pacu, Piaractus mesopotamicus, were used to validate de accuracy of those methods. Meyer & Fracalossi's and Tacon's methodology estimated the lysine requirement of pacu, respectively, at 13 and 23% above requirement determined using dose-response method. The values estimated by both methods lie within the range of requirements determined for other omnivorous fish species, the Meyer & Fracalossi (2005 method showing better accuracy.

Full Text Available Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected aminoacid synthesis. Here, using a supercritical CO2/liquid H2O (10:1 system which mimicked crust soda fountains, we demonstrate production of aminoacids from hydroxylamine (nitrogen source and keto acids (oxylic acid sources. In this research, several aminoacids were detected with an aminoacid analyzer. Moreover, alanine polymers were detected with LC-MS. Our research lights up a new pathway in the study of life’s origin.

Full Text Available In this work, oxidized nanocellulose (ONC was synthesized and chemically coupled with aminoacids and peptides using a two step coupling method at room temperature. First, ONC was activated by N-ethyl-N’-(3-dimethylaminopropyl carbodiimide hydrochloride, forming a stable active ester in the presence of N-hydroxysuccinimide. Second, the active ester was reacted with the amino group of the aminoacid or peptide, forming an amide bond between ONC and the grafted molecule. Using this method, the intermolecular interaction of aminoacids and peptides was avoided and uniform coupling of these molecules on ONC was achieved. The coupling reaction was very fast in mild conditions and without alteration of the polysaccharide. The coupling products (ONC-aminoacids and ONC-peptides were characterized by transmission electron microscopy and by the absorption, emission, Fourier transform infrared spectroscopy (FTIR and X-ray photoelectron spectroscopy (XPS spectroscopic techniques.

Ostwald solubility (L) of xenon gas, as the radioisotope 133Xe, has been measured as a function of solute concentration, at 25.0 °C, in aqueous solutions of nine aminoacids. The amino-acid concentrations investigated covered much of their solubility ranges in water, viz., asparagine monohydrate (0-0.19 M), cysteine (0-1.16 M), glutamine (0-0.22 M), histidine (0-0.26 M), isoleucine (0-0.19 M), methionine (0-0.22 M), serine (0-0.38 M), threonine (0-1.4 M), and valine (0-0.34 M). We have previously reported solubility results for aqueous solutions of six other, generally more soluble, aminoacids (alanine, arginine, glycine, hydroxyproline, lysine, and proline), of sucrose and sodium chloride. In general, L decreases approximately linearly with increasing solute concentration in these solutions. If we postulate that the observed decreases in gas solubility are due to hydration, the results under some assumptions can be used to calculate hydration numbers (H), i.e., the number of H2O molecules associated with each amino-acid solute molecule. The average values of hydration number (H¯) obtained at 25.0 °C are 15.3±1.5 for asparagine, 6.8±0.3 for cysteine, 11.5±1.1 for glutamine, 7.3±0.7 for histidine, 5.9±0.4 for isoleucine, 10.6±0.8 for methionine, 11.2±1.3 for serine, 7.7± 1.0 for threonine, and 6.6±0.6 for valine. We have also measured the temperature dependence of solubility L(T) from 5-40 °C for arginine, glycine, and proline, and obtained hydration numbers H¯(T) in this range. Between 25-40 °C, arginine has an H¯ near zero. This may be evidence for an attractive interaction between xenon and arginine molecules in aqueous solution.

Disorders of aminoacid metabolism or transport are most clearly expressed in urine. Nevertheless the interpretation of abnormalities in urinary aminoacid excretion remains difficult. An increase or decrease of almost every aminoacid in urine can be due to various etiology. To differentiate between primary and secondary aminoacido-pathies systematic laboratory investigation is necessary. Early diagnosis of disorders of aminoacid metabolism or transport is very important, because most of them can be treated, leading to the prevention of (further) clinical abnormalities. In those disorders, which cannot be treated, early diagnosis in an index-patient may prevent the birth of other siblings by means of genetic counseling and prenatal diagnosis.Primary aminoacidopathies can be due to genetically determined transport disorders and enzyme deficiencies in aminoacid metabolism or degradation. Secondary aminoacidopathies are the result of abnormal or deficient nutrition, intestinal dysfunction, organ pathology or other metabolic diseases like organic acidurias.A survey of aminoacid metabolism and transport abnormalities will be given, illustrated with metabolic pathways and characteristic abnormal aminoacid chromatograms.

The microbial degradation of proteins, peptides and aminoacids generates volatiles involved in the typical flavor of dry fermented sausage. The ability of three Lactobacillus sakei strains to form aroma compounds was investigated. Whole resting cells were fermented in phosphate buffer with equimolar amounts of substrates consisting of dipeptides, tetrapeptides and free aminoacids, respectively. Dipeptides disappeared quickly from the solutions whereas tetrapeptides were only partially degraded. In both approaches the concentration of free aminoacids increased in the reaction mixture but did not reach the equimolar amount of the initial substrates. When free aminoacids were fed to the bacteria their levels decreased only slightly. Although peptides were more rapidly degraded and/or transported into the cells, free aminoacids produced higher amounts of volatiles. It is suggested, that after transport into the cell peptides are only partially hydrolyzed to their aminoacids, while the rest is metabolized via alternative metabolic pathways. The three L. sakei strains differed to some extend in their ability to metabolize the substrates to volatile compounds. In a few cases this was due to the position of the aminoacids within the peptides. Compared to other starter cultures used for the production of dry fermented sausages, the metabolic impact of the L. sakei strains on the formation of volatiles was very low.

Currently, several types of aminoacids are being produced and used worldwide. Nevertheless, several new functions of aminoacids have been recently discovered that could result in other applications. For example, oral stimulation by glutamate triggers the cephalic phase response to prepare for food digestion. Further, the stomach and intestines have specific glutamate-recognizing systems in their epithelial mucosa. Regarding clinical applications, addition of monosodium glutamate to the medicinal diet has been shown to markedly enhance gastric secretion in a vagus-dependent manner. Branched-chain aminoacids (BCAAs) are the major components of muscles, and ingestion of BCAAs has been found to be effective for decreasing muscle pain. BCAAs are expected to be a solution for the serious issue of aging. Further, ingestion of specific aminoacids could be beneficial. Glycine can be ingested for good night's sleep: glycine ingestion before bedtime significantly improved subjective sleep quality. Ingestion of alanine and glutamine effectively accelerates alcohol metabolism, and ingestion of cystine and theanine effectively prevents colds. Finally, aminoacids could be used in a novel clinical diagnostic method: the balance of aminoacids in the blood could be an indicator of the risk of diseases such as cancer. These newly discovered functions of aminoacids are expected to contribute to the resolution of various issues.

The three aromatic aminoacids, tyrosine, tryptophan and phenylalanine, play different physiological roles in life processes. Metal ions capable of binding these aminoacids may aid in the reduction of effective concentration of these aminoacids in any physiological system. Here we have studied the efficacy of some heavy metals for their complexation with these three aminoacids. Bismuth has been found to bind selectively with these aromatic aminoacids and this was confirmed using spectrofluorimetric, spectrophotometric and cyclic voltammetric studies. The series of heavy metals has been chosen because each of these metals remains associated with the others at very low concentration levels and Bi(III) is the least toxic amongst the other elements. So, selective recognition for Bi(III) would also mean no response for the other heavy elements if contaminants are present even at low concentration levels. The affinity towards these aminoacids has been found to be in the order tryptophan phenylalanine aminoacids have been calculated using Benesi-Hildebrand equations and the corresponding free energy change has also been calculated. The values of the association constants obtained from BH equations using absorbance values corroborate with the Stern-Volmer constants obtained from fluorimetric studies. The evidence for complexation is also supported by the results of cyclic voltammetry.

Full Text Available For human nutrition the main source of vegetable proteins are cereal and legume seeds. The content of total soluble aminoacids in mature endosperm of wild-type, opaque and floury maize (Zea mays L. mutants were determined by HPLC. The total absolute concentration of soluble aminoacids among the mutants varied depending on the mutant. The o11 and o13 mutants exhibited the highest average content, whereas o10, fl3 and fl1 exhibited the lowest average content. In general, the mutants exhibited similar concentrations of total soluble aminoacids when compared to the wild-type lines, with the clear exception of mutants o11 and fl1, with the o11 mutant exhibiting a higher concentration of total soluble aminoacids when compared to its wild-type counterpart W22 and the fl1 mutant a lower concentration when compared to its wild-type counterpart Oh43. For methionine, the mutants o2 and o11 and wild-type Oh43 exhibited the highest concentrations of this aminoacid. Significant differences were not observed between mutants for other aminoacids such as lysine and threonine. The high lysine concentrations obtained originally for these mutants may be due to the aminoacids incorporated into storage proteins, but not those present in the soluble form.

There is a dire need to discover new targets for Alzheimer's disease (AD) drug development. Decreased neuronal glucose metabolism that occurs in AD brain could play a central role in disease progression. Little is known about the compensatory neuronal changes that occur to attempt to maintain energy homeostasis. In this review using the PubMed literature database, we summarize evidence that aminoacid oxidation can temporarily compensate for the decreased glucose metabolism, but eventually altered aminoacid and aminoacid catabolite levels likely lead to toxicities contributing to AD progression. Because aminoacids are involved in so many cellular metabolic and signaling pathways, the effects of altered aminoacid metabolism in AD brain are far-reaching. Possible pathological results from changes in the levels of several important aminoacids are discussed. Urea cycle function may be induced in endothelial cells of AD patient brains, possibly to remove excess ammonia produced from increased aminoacid catabolism. Studying AD from a metabolic perspective provides new insights into AD pathogenesis and may lead to the discovery of dietary metabolite supplements that can partially compensate for alterations of enzymatic function to delay AD or alleviate some of the suffering caused by the disease. PMID:28261376

Large quantities of NO(x) and N(2)O emissions can be produced from biomass burning. Understanding nitrogen behavior during biomass pyrolysis is crucial. Nitrogen in biomass is mainly in forms of proteins (aminoacids). Phenylalanine, aspartic acid, and glutamic acid were used as the model compounds for the nitrogen in biomass. Release behavior tests of nitrogen species from the three aminoacids during pyrolysis in argon and gasification with O(2) and CO(2) were performed using a thermogravimetric analyzer (TGA) coupled with a Fourier transform infrared (FTIR) spectrometer. The results indicate that although the influence of oxygen and CO(2) in the atmosphere on nitrogen behavior is different for the aminoacids, it is interesting to find some phenomenon in common. The presence of oxygen promotes NO and HNCO formation for all the three aminoacids; HCN and HNCO formation are suppressed by introduced CO(2) for all the three aminoacids. This can reveal the N-conversion mechanism from biomass in depth under the same conditions.

Coral reefs are one of the most important marine ecosystems, providing habitat for approximately a quarter of all marine organisms. Within the foundation of this ecosystem, reef-building corals form mutualistic symbioses with unicellular photosynthetic dinoflagellates of the genus Symbiodinium. Exposure to UV radiation (UVR) (280 to 400 nm) especially when combined with thermal stress has been recognized as an important abiotic factor leading to the loss of algal symbionts from coral tissue and/or a reduction in their pigment concentration and coral bleaching. UVR may damage biological macromolecules, increase the level of mutagenesis in cells, and destabilize the symbiosis between the coral host and their dinoflagellate symbionts. In nature, corals and other marine organisms are protected from harmful UVR through several important photoprotective mechanisms that include the synthesis of UV-absorbing compounds such as mycosporine-like aminoacids (MAAs). MAAs are small (<400-Da), colorless, water-soluble compounds made of a cyclohexenone or cyclohexenimine chromophore that is bound to an aminoacid residue or its imino alcohol. These secondary metabolites are natural biological sunscreens characterized by a maximum absorbance in the UVA and UVB ranges of 310 to 362 nm. In addition to their photoprotective role, MAAs act as antioxidants scavenging reactive oxygen species (ROS) and suppressing singlet oxygen-induced damage. It has been proposed that MAAs are synthesized during the first part of the shikimate pathway, and recently, it has been suggested that they are synthesized in the pentose phosphate pathway. The shikimate pathway is not found in animals, but in plants and microbes, it connects the metabolism of carbohydrates to the biosynthesis of aromatic compounds. However, both the complete enzymatic pathway of MAA synthesis and the extent of their regulation by environmental conditions are not known. This minireview discusses the current knowledge of MAA

A periodic table of codons has been designed where the codons are in regular locations. The table has four fields (16 places in each) one with each of the four nucleotides (A, U, G, C) in the central codon position. Thus, AAA (lysine), UUU (phenylalanine), GGG (glycine), and CCC (proline) were placed into the corners of the fields as the main codons (and aminoacids) of the fields. They were connected to each other by six axes. The resulting nucleic acid periodic table showed perfect axial symmetry for codons. The corresponding aminoacid table also displaced periodicity regarding the biochemical properties (charge and hydropathy) of the 20 aminoacids and the position of the stop signals. The table emphasizes the importance of the central nucleotide in the codons and predicts that purines control the charge while pyrimidines determine the polarity of the aminoacids. This prediction was experimentally tested.

Aminoacid mutations in proteins can be found by searching tandem mass spectra acquired in shotgun proteomics experiments against protein sequences predicted from genomes. Traditionally, unconstrained searches for aminoacid mutations have been accomplished by using a sequence tagging approach that combines de novo sequencing with database searching. However, this approach is limited by the performance of de novo sequencing. The Sipros algorithm v2.0 was developed to perform unconstrained database searching using high-resolution tandem mass spectra by exhaustively enumerating all single non-isobaric mutations for every residue in a protein database. The performance of Sipros for aminoacid mutation identification exceeded that of an established sequence tagging algorithm, Inspect, based on benchmarking results from a Rhodopseudomonas palustris proteomics dataset. To demonstrate the viability of the algorithm for meta-proteomics, Sipros was used to identify aminoacid mutations in a natural microbial community in acid mine drainage.

We analyzed the aminoacid content of seven lunar regolith samples returned by the Apollo 16 and Apollo 17 missions and stored under NASA curation since collection using ultrahigh-performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Consistent with results from initial analyses shortly after collection in the 1970s, we observed aminoacids at low concentrations in all of the curated samples, ranging from 0.2 parts-per-billion (ppb) to 42.7 ppb in hot-water extracts and 14.5-651.1 ppb in 6 M HCl acid-vapor-hydrolyzed, hot-water extracts. Aminoacids identified in the Apollo soil extracts include glycine, D- and L-alanine, D- and L-aspartic acid, D- and L-glutamic acid, D- and L-serine, L-threonine, and L-valine, all of which had previously been detected in lunar samples, as well as several compounds not previously identified in lunar regoliths: α-aminoisobutyric acid (AIB), D- and L-β-amino-n-butyric acid (β-ABA), DL-α-amino-n-butyric acid, γ-amino-n-butyric acid, β-alanine, and ε-amino-n-caproic acid. We observed an excess of the L enantiomer in most of the detected proteinogenic aminoacids, but racemic alanine and racemic β-ABA were present in some samples. We also examined seven samples from Apollo 15, 16, and 17 that had been previously allocated to a non-curation laboratory, as well as two samples of terrestrial dunite from studies of lunar module engine exhaust that had been stored in the same laboratory. The aminoacid content of these samples suggested that contamination had occurred during non-curatorial storage. We measured the compound-specific carbon isotopic ratios of glycine, β-alanine, and L-alanine in Apollo regolith sample 70011 and found values of -21‰ to -33‰. These values are consistent with those seen in terrestrial biology and, together with the enantiomeric compositions of the proteinogenic aminoacids, suggest that terrestrial biological contamination is a primary source of the

Different nitrogen (N) forms may cause changes in the metabolic profiles of plants. However, few studies have been conducted on the effects of aminoacid-N on plant metabolic proifles. The main objective of this study was to identify primary metabolites associated with aminoacid-N (Gly, Gln and Ala) through metabolic proifle analysis using gas chromatography-mass spectrometry (GC-MS). Plants of pakchoi (Brassica campestris L. ssp. chinensis L.), Huawang and Wuyueman cultivars, were grown with different nitrogen forms (i.e., Gly, Gln, Ala, NO3--N, and N starvation) applied under sterile hydroponic conditions. The fresh weight and plant N accumulation of Huawang were greater than those of Wuyueman, which indicates that the former exhibited better N-use efficiency than the latter. The physiological performances of the applied N forms were generally in the order of NO3--N>Gln>Gly>Ala. The metabolic analysis of leaf polar extracts revealed 30 aminoacid N-responsive metabolites in the two pakchoi cultivars, mainly consisting of sugars, aminoacids, and organic acids. Changes in the carbon metabolism of pakchoi leaves under aminoacid treatments occurred via the accumulation of fructose, glucose, xylose, and arabinose. Disruption of aminoacid metabolism resulted in accumulation of endogenous Gly in Gly treatment, Pro in Ala treatment, and Asn in three aminoacid (Gly, Gln and Ala) treatments. By contrast, the levels of endogenous Gln and Leu decreased. However, this reduction varied among cultivars and aminoacid types. Aminoacid-N supply also affected the citric acid cycle, namely, the second stage of respiration, where leaves in Gly, Gln and Ala treatments contained low levels of malic, citric and succinic acids compared with leaves in NO3--N treatments. No signiifcant difference in the metabolic responses was observed between the two cultivars which differed in their capability to use N. The response of primary metabolites in pakchoi leaves to aminoacid-N supply

Single nucleotide polymorphism (SNP) studies and random mutagenesis projects identify aminoacid substitutions in protein-coding regions. Each substitution has the potential to affect protein function. SIFT (Sorting Intolerant From Tolerant) is a program that predicts whether an aminoacid substitution affects protein function so that users can prioritize substitutions for further study. We have shown that SIFT can distinguish between functionally neutral and deleterious aminoacid changes in mutagenesis studies and on human polymorphisms. SIFT is available at http://blocks.fhcrc.org/sift/SIFT.html.

Full Text Available The article is a review of current literature on a content of proteins, peptides and aminoacids in human exhaled breath. The results of proteomics and metabolomics applying for selective detection of individual proteins, peptides and aminoacids are described. The study of exhaled breath condensate and exhaled endogenous particles contained lung proteins are considered. The peculiarities of protein, peptide and aminoacid content in exhaled breath at various respiratory diseases are described. It is shown that the detectable substances may be specific markers of individual diseases.

Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (aminoacids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several aminoacids: tryptophan, leucine, phenylalanine, serine and tyrosine. These aminoacids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (aminoacids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several aminoacids: tryptophan, leucine, phenylalanine, serine and tyrosine. These aminoacids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

The objective of this study was to investigate transepithelial aminoacid transport as a function of Caco-2 cell culture time. Furthermore, the objective was to investigate apical uptake characteristics of hPAT1-mediated transport under various experimental conditions. Apical aminoacid uptake......, which has been shown to function as a carboxylic acid bioisostere for substrates of the GABA receptor and transport systems....

The synthesis of proteins bearing unnatural aminoacids has the potential to enhance and elucidate many processes in biochemistry and molecular biology. There are two primary methods for site specific unnatural aminoacid incorporation, both of which use the cell’s native protein translating machinery: in vitro chemical acylation of suppressor tRNAs and the use of orthogonal amino acyl tRNA synthetases. Total chemical synthesis is theoretically possible, but current methods severely limit the maximum size of the product protein. In vivo orthogonal synthetase methods suffer from the high cost of the unnatural aminoacid. In this thesis I sought to address this limitation by increasing cell density, first in shake flasks and then in a bioreactor in order to increase the yield of protein per amount of unnatural aminoacid used. In a parallel project, I used the in vitro chemical acylation system to incorporate several unnatural aminoacids, key among them the fluorophore BODIPYFL, with the aim of producing site specifically fluorescently labeled protein for single molecule FRET studies. I demonstrated successful incorporation of these aminoacids into the trial protein GFP, although incorporation was not demonstrated in the final target, FEN1. This also served to confirm the effectiveness of a new procedure developed for chemical acylation.

The free amino (0.3 equiv/residue) and carboxyl (0.5 equiv/residue) groups of thermal polylysine increased dramatically on treatment with distilled water. The total hydrolysis of such a polymer was abnormal in that only about 50% of the expected aminoacids were recovered. Poly (lysine-co-alanine-co-glycine) under usual conditions hydrolyzed completely in 8 hours; whereas, when it was pretreated with diazomethane, a normal period of 24 hours was required to give (nearly) the same amounts of each free aminoacid as compared with those obtained from the untreated polymer. The amino groups of the basic thermal poly(aminoacids) were sterically hindered. The existence of nitrogen atoms linking two or three chains and reactive groups (anhydride, imine) were proposed.

Aminoacids can serve as important markers of cosmochemistry, as their abundances and isomeric and isotopic compositions have been found to vary predictably with changes in parent body chemistry and alteration processes. Aminoacids are also of astrobiological interest because they are essential for life on Earth. Analyses of a range of meteorites, including all groups of carbonaceous chondrites, along with H, R, and LL chondrites, ureilites, and a martian shergottite, have revealed that aminoacids of plausible extraterrestrial origin can be formed in and persist after a wide range of parent body conditions. However, aminoacid analyses of L6 chondrites to date have not provided evidence for indigenous aminoacids. In the present study, we performed aminoacid analysis on larger samples of a different L6 chondite, Canakkale, to determine whether or not trace levels of indigenous aminoacids could be found. The Canakkale meteor was an observed fall in late July, 1964, near Canakkale, Turkey. The meteorite samples (1.36 and 1.09 g) analyzed in this study were allocated by C. Y. Ornek, along with a soil sample (1.5 g) collected near the Canakkale recovery site.

Resorption of aminoacids in kidney and intestine is mediated by transporters, which prefer groups of aminoacids with similar physico-chemical properties. It is generally assumed that most neutral aminoacids are transported across the apical membrane of epithelial cells by system B(0). Here we have characterized a novel member of the Na(+)-dependent neurotransmitter transporter family (B(0)AT1) isolated from mouse kidney, which shows all properties of system B(0). Flux experiments showed that the transporter is Na(+)-dependent, electrogenic, and actively transports most neutral aminoacids but not anionic or cationic aminoacids. Superfusion of mB(0)AT1-expressing oocytes with neutral aminoacids generated inward currents, which were proportional to the fluxes observed with labeled aminoacids. In situ hybridization showed strong expression in intestinal microvilli and in the proximal tubule of the kidney. Expression of mouse B(0)AT1 was restricted to kidney, intestine, and skin. It is generally assumed that mutations of the system B(0) transporter underlie autosomal recessive Hartnup disorder. In support of this notion mB(0)AT1 is located on mouse chromosome 13 in a region syntenic to human chromosome 5p15, the locus of Hartnup disorder. Thus, the human homologue of this transporter is an excellent functional and positional candidate for Hartnup disorder.

Physiological conditions in humans affect plasma aminoacid profiles that might have potential for medical use. Because the branched-chain aminoacids (BCAAs) leucine, isoleucine and valine are used as medicines and supplements, we investigated the acute effects of individual BCAAs (10-90 mg/kg body weight) or mixed BCAAs ingested as a bolus on plasma aminoacid profiles in young healthy men. Plasma leucine levels rapidly increased and peaked around 30 min after leucine ingestion. Concentrations of plasma isoleucine, valine and phenylalanine subsequently decreased after ingestion, and those of methionine and tyrosine tended to decrease. The effects of ingested leucine on other plasma aminoacids were biphasic, being higher at lower doses (10-20 mg/kg body weight). Isoleucine or valine intake also caused corresponding plasma aminoacid concentrations to rapidly elevate, and peaks at 30-40 min after ingestion were much higher than that of plasma leucine after leucine ingestion. However, the increase in plasma isoleucine and valine concentrations essentially did not affect those of other plasma aminoacids. The rate of decline among peak plasma BCAA concentrations was the highest for leucine, followed by isoleucine and valine. Oral mixed BCAAs promoted the decline in plasma isoleucine and valine concentrations. These results suggest that plasma leucine is a regulator of the plasma concentrations of BCAAs, methionine and aromatic aminoacids.

In contrast to the Murchison meteorite which had a complex distribution of aminoacids with a total C2 to Cs aminoacid abundance of approx.14,000 parts-per-billion (ppb) [2], the Sutters Mill meteorite was found to be highly depleted in aminoacids. Much lower abundances (approx.30 to 180 ppb) of glycine, beta-alanine, L-alanine and L-serine were detected in SM2 above procedural blank levels indicating that this meteorite sample experienced only minimal terrestrial aminoacid contamination after its fall to Earth. Carbon isotope measurements will be necessary to establish the origin of glycine and beta-alanine in SM2. Other non-protein aminoacids that are rare on Earth, yet commonly found in other CM meteorites such as aaminoisobutyric acid (alpha-AIB) and isovaline, were not identified in SM2. However, traces of beta-AIB (approx.1 ppb) were detected in SM2 and could be" extraterrestrial in origin. The low abundances of aminoacids in the Sutter's Mill meteorite is consistent with mineralogical evidence that at least some parts of the Sutter's Mill meteorite parent body experienced extensive aqueous and/or thermal alteration.

L-Aminoacids find various applications in biotechnology. L-Glutamic acid and its salts are used as flavor enhancers. Other L-aminoacids are used as food or feed additives, in parenteral nutrition or as building blocks for the chemical and pharmaceutical industries. L-aminoacids are synthesized from precursors of central carbon metabolism. Based on the knowledge of the biochemical pathways microbial fermentation processes of food, feed and pharma aminoacids have been developed. Production strains of Corynebacterium glutamicum, which has been used safely for more than 50 years in food biotechnology, and Escherichia coli are constantly improved using metabolic engineering approaches. Research towards new processes is ongoing. Fermentative production of L-aminoacids in the million-ton-scale has shaped modern biotechnology and its markets continue to grow steadily. This review focusses on recent achievements in strain development for aminoacid production including the use of CRISPRi/dCas9, genome-reduced strains, biosensors and synthetic pathways to enable utilization of alternative carbon sources.

Graphene sheets were covalently functionalized with aromatic–aliphatic aminoacids (phenylalanine and tyrosine) and aliphatic aminoacids (alanine, isoleucine, leucine, methionine and valine) by simple and green procedure. For this aim, at first natural graphite was converted into graphene oxide (GO) through strong oxidation procedure; then, based on the surface-exposed epoxy and carboxylic acid groups in GO solid, its surface modification with naturally occurring aminoacids, occurred easily throughout the corresponding nucleophilic substitution and condensation reactions. Aminoacid functionalized graphene demonstrates stable dispersion in water and common organic solvents. Fourier transform infrared, Raman and X-ray photoelectron spectroscopies, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy were used to investigate the nanostructures and properties of prepared materials. Each aminoacid has different considerable effects on the structure and morphology of the pure graphite, from increasing the layer spacing to layer scrolling, based on their structures, functional groups and chain length. In addition, therogravimetric analysis was used for demonstrating a successful grafting of aminoacid molecules to the surface of graphene.

Full Text Available Flying fish are found in waters of eastern Indonesia, which until now is still limited information about nutritional content. The purpose of this research was determine the composition of fatty acids, aminoacids, total carotenoids, α-tocopherol flying fish eggs (Hyrundicthys sp.. The composition of fatty acid was measured by gas chromatography (GC, while aminoacids, total carotenoids, α-tocopherol was measured by High performanced Liquid Chromatography (HPLC. Egg contained 22 fatty acids such as saturated fatty acid 29.71%, monounsaturated fatty acid 7.86%, and polysaturated fatty acid 13.64%. The result showed that eggs flying fish contained 17 aminoacids, such as essential aminoacid 14.96% and non-essential aminoacids 20.27%. Eggs contained a total carotenoid of 245.37 ppm. α-tocopherol content of flying fish eggs by 1.06 ppm.

Full Text Available A three-week trial was conducted to determine the effect of lowering dietary protein level (DPL with optimal aminoacid (AA profile on growth performance, blood metabolites, and relative weights of abdominal fat and internal organs in broiler chickens raised under tropical hot and humid environment. Five isocaloric (3023 metabolisable energy/kg starter (1-21 days experimental diets were formulated in a gradual crude protein (CP decline from 22.2 (control to 16.2% by 1.5% interval. All diets were meeting or exceeding National Research Council recommendations except CP and metabolisable energy. The formulations were also adjusted to contain 1.1 digestible Lys to meet the ideal AA ratios concept. Body weights (BW, weight gains (WG, feed intake and feed conversion ratio of groups with 19.2, 20.7 and 22.2% DPL were not significantly different. However, BW and WG suppressed (P<0.05 with 16.2 and 17.7% DPL. Feeding the 16.2% CP diet significantly reduced serum total protein and uric acid, but increased serum triglyceride (P<0.05. Moreover, relative heart weights increased (P<0.05 but no changes occurred in liver and abdominal fat weights in chicks with 16.2% DPL. In summary, CP of broilers starter (1-21 days diet can be reduced till 19.2% with essential AA fortification and without any adverse effect on growth performance under the hot, humid tropics.

To meet the growing demands for the development of new molecular entities for discovering new drugs and materials, organic chemists have started working on many new concepts that can help to assimilate knowledge-based structural diversities more efficiently than ever before. Emulating the basic principles followed by Nature to build its vast repertoire of biomolecules, organic chemists are developing many novel multifunctional building blocks and using them to create `nature-like’ and yet unnatural organic molecules. Sugar aminoacids constitute an important class of such polyfunctional scaffolds where the carboxyl, amino and hydroxyl termini provide an excellent opportunity to organic chemists to create structural diversities akin to Nature’s molecular arsenal. In recent years, sugar aminoacids have been used extensively in the area of peptidomimetic studies. Advances made in the area of combinatorial chemistry can provide the necessary technological support for rapid compilations of sugar amino acidbased libraries exploiting the diversities of their carbohydrate frameworks and well-developed solidphase peptide synthesis methods. This perspective article chronicles some of the recent applications of various sugar aminoacids, furan aminoacids, pyrrole aminoacids etc. and many other related building blocks in wide-ranging peptidomimetic studies.

Nov 15, 1998 ... Duodenal and whole empty body essential aminoacid proﬁle ... determining growth requirements of the South African Mutton ... to only a limited extent in the liver and thus their concentration in the extra hepatic blood circula-.

Aug 10, 2011 ... L-Arginine has been used to improve endothelial function by increasing nitric ... between HD patients with and without history of thromboembolic manifestations. ... Plasma protein and aminoacid concentrations have been.

Full Text Available , antimicrobials, and as nonstandard aminoacids in therapeutic peptides or peptidomimetics. Access to these compounds can be achieved through diverse synthetic routes with enantioselective steps catalyzed in different ways, including by means of nitrile hydrolysis...

Aminoacids are attractive and promising biochemicals with market capacity requirements constantly increasing. Their applicability ranges from animal feed additives, flavour enhancers and ingredients in cosmetic to specialty nutrients in pharmaceutical and medical fields. This review gives...... an overview of the processes applied for aminoacids production and points out the main advantages and disadvantages of each. Due to the advances made in the genetic engineering techniques, the biotechnological processes, and in particular the fermentation with the aid of strains such as Corynebacterium...... glutamicum or Escherichia coli, play a significant role in the industrial production of aminoacids. Despite the numerous advantages of the fermentative aminoacids production, the process still needs significant improvements leading to increased productivity and reduction of the production costs. Although...

Current theories on the origin of life reveal significant gaps in our understanding of the mechanisms that allowed simple chemical precursors to coalesce into the complex polymers that are needed to sustain life. The volcanic gas carbonyl sulfide (COS) is known to catalyze the condensation of aminoacids under aqueous conditions, but the reported di-, tri-, and tetra-peptides are too short to support a regular tertiary structure. Here, we demonstrate that alanine and valine, two of the proteinogenic aminoacids believed to have been among the most abundant on a prebiotic earth, can polymerize into peptides and subsequently assemble into ordered amyloid fibers comprising a cross-β-sheet quaternary structure following COS-activated continuous polymerization of as little as 1 mm aminoacid. Furthermore, this spontaneous assembly is not limited to pure aminoacids, since mixtures of glycine, alanine, aspartate, and valine yield similar structures.

BACKGROUND: Global residue-specific aminoacid mutagenesis can provide important biological insight and generate proteins with altered properties, but at the risk of protein misfolding. Further, targeted libraries are usually restricted to a handful of aminoacids because there is an exponential...... correlation between the number of residues randomized and the size of the resulting ensemble. Using GFP as the model protein, we present a strategy, termed protein evolution via aminoacid and codon elimination, through which simplified, native-like polypeptides encoded by a reduced genetic code were obtained...... simultaneously), while retaining varying levels of activity. Combination of these substitutions to generate a Phe-free variant of GFP abolished fluorescence. Combinatorial re-introduction of five Phe residues, based on the activities of the respective single aminoacid replacements, was sufficient to restore GFP...

Meteorites are grouped according to bulk properties such as chemical composition and mineralogy. These parameters can vary significantly among the different carbonaceous chondrite groups (CI, CM, CO, CR, CH, CB, CV and CK). We have determined the aminoacid abundances of more than 30 primary aminoacids in meteorites from each of the eight groups, revealing several interesting trends. There are noticeable differences in the structural diversity and overall abundances of aminoacids between meteorites from the different chondrite groups. Because meteorites may have been an important source of aminoacids to the prebiotic Earth and these organic compounds are essential for life as we know it, the observed variations of these molecules may have been important for the origins of life.

BACKGROUND: Excitatory aminoacid transporters (EAATs) are transmembrane proteins responsible for the uptake of (S)-glutamate (Glu) from the synaptic cleft, thereby terminating the glutamatergic neurotransmitter signal. Today five subtypes have been identified. Except for EAAT2, their individual...

Cultural heritage parchments made from the reticular dermis of animals have been subject to studies of deterioration and conservation by aminoacid analysis. The reticular dermis contains a varying mixture of collagen I and III (COL I and III). When dealing with the results of the aminoacid...... analyses, till now the COL III content has not been taken into account. Based on the available aminoacid sequences we present a method for determining the amount of COL III in the reticular dermis of new and historical parchments calculated from the ratio of Ile/Val. We find COL III contents between 7...... and 32 % in new parchments and between 0.2 and 40 % in the historical parchments. This is consistent with results in the literature. The varying content of COL III has a significant influence on the uncertainty of the aminoacid analysis. Although we have not found a simple correlation between the COL...

essential aminoacids needed for enhanced nutrition. ... Edible seeds are important sources of nutrients and energy especially among the ... Likewise, edible seeds can sustain livestock production by ensuring the availability of various sources ...

A large number of modified aminoacids other than the canonical aminoacid residues can be found in natural products, especially antibiotics. The structure of these peptide-based compounds is investigated using modern two-dimensional NMR techniques. The automatic assignment of the 2D NMR proton spectra and consequent determination of the primary and 3D structure of peptides or small size proteins containing natural aminoacids is nowadays routine. However, a deficiency in the ability to readily sequence peptides containing unnatural aminoacids still remains and a great human effort and time is required. The experimental methods and the protocols of manual analysis of the data are described in the following sections.

With the emergence of the copper-catalysed Huisgen cycloaddition the use of azide- and alkyne-derivatised α-aminoacids has found widespread use within most chemistry disciplines. Despite a growing interest in these building blocks researchers are struggling to identify the best way...... for their synthesis. In this review we have compiled available methods for synthesising optically active azide- and alkyne-derivatised α-aminoacids that can be prepared from readily available α-aminoacids. We highlight a number of commonly overlooked problems associated with existing methods and direct attention...... to unexplored possibilities. Azide- and alkyne-derivatised α-aminoacids are finding widespread use within most chemistry disciplines. However, it is far from clear what the best way for the synthesis of these useful building blocks is. Herein we show the available methods for synthesis of optically active...

Phosphorylation of serine, threonine, and tyrosine residues is the archetypal posttranslational modification of proteins. While phosphorylation of these residues has become standard textbook knowledge, phosphorylation of other aminoacid side chains is underappreciated and minimally characterized by comparison. This disparity is rooted in the relative instability of these chemically distinct aminoacid side chain moieties, namely phosphoramidates, acyl phosphates, thiophosphates, and phosphoanhydrides. In the case of the O-phosphorylated aminoacids, synthetic constructs were critical to assessing their stability and developing tools for their study. As the chemical biology community has become more aware of these alternative phosphorylation sites, methodology has been developed for the synthesis of well-characterized standards and close mimics of these phosphorylated aminoacids as well. In this article, we review the synthetic chemistry that is a prerequisite to progress in this field.

Full Text Available Blood levels of the aminoacid phenylalanine, as well as of the tryptophan breakdown product kynurenine, are found to be elevated in human immunodeficiency virus type 1 (HIV-1-infected patients. Both essential aminoacids, tryptophan and phenylalanine are important precursor molecules for neurotransmitter biosynthesis. Thus, dysregulated aminoacid metabolism may be related to disease-associated neuropsychiatric symptoms such as development of depression, fatigue, and cognitive impairment.Increased phenylalanine/tyrosine and kynurenine/tryptophan ratios are associated with immune activation in patients with HIV-1 infection and decrease upon effective antiretroviral therapy. Recent large-scale metabolic studies have confirmed the crucial involvement of tryptophan and phenylalanine metabolism in HIV-associated disease. Herein, we summarize the current status of the role of tryptophan and phenylalanine metabolism in HIV disease and discuss how inflammatory stress-associated dysregulation of aminoacid metabolism may be part of the pathophysiology of common HIV-associated neuropsychiatric conditions.

The use of aminoacid based dendrimers as molecular scaffolds for the attachment of catalytically active organometallic Ni ''pincer'' complexes, via a urea functionality, is described; the dendrimer catalysts have comparable activity to their mononuclear (NCN)NiX analogues.

A fluidic-chip based instrument for subcritical water extraction (SCWE) of aminoacids and other organics from powder samples has been developed. A variety of soil analog extractions have been performed to better understand SCWE capabilities.

The study of nanomaterial/biomolecule interface is an important emerging field in bionanoscience, and additionally in many biological processes such as hard-tissue growth and cell-surface adhesion. To have a deeper understanding of the aminoacids/gold nanoparticle assemblies, the adsorption of these aminoacids on the gold nanoparticles (GNPs) has been investigated via molecular dynamics simulation. In these simulations, all the constituent atoms of the nanoparticles were considered to be dynamic. The geometries of aminoacids, when adsorbed on the nanoparticle, were studied and their flexibilities were compared with one another. The interaction of each of 20 aminoacids was considered with 3 and 8 nm gold GNPs.

Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic aminoacids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential aminoacid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular aminoacids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of aminoacids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.

Background A number of reports based on both animal experiments and clinical investigations have pointed out that total parenteral nutrition (TPN) suppresses the function of the exocrine pancreas. Even though pancreatic hypotrophy and dysfunction resulting from TPN may be explained by several mechanisms, the clinically most important cause is that nutrients in circulation affect pancreatic secretion. The effect of nutrients on the exocrine pancreas is still controversial. The aim of the present study was, therefore, to clarify the influence of intravenous aminoacids and hypertonic glucose in TPN solution on the exocrine pancreas. Methods Three mixed TPN solutions, consisting of 30% or 50% glucose or of 14% aminoacids, were employed. Twenty-four male Sprague-Dawley rats were randomly divided into four groups, six rats in each group, including a control group and one group receiving each of the three TPN solutions. All animals were killed after 10 days of TPN. Body weight, pancreatic content, and enzyme levels in the pancreas were measured. Results Compared with the control group, pancreatic wet weight was lower in all TPN groups. Glucose significantly decreased the content and concentration of pancreatic protein, but aminoacids did not alter the concentration of protein. The level of amylase was lower in all parenterally fed groups, with a greater decrease in the groups treated with aminoacids and 30% glucose than with 50% glucose. Trypsin levels in all groups receiving TPN were markedly higher than in the control group. Conclusion TPN results in atrophy of the pancreas, but trypsin levels increase with TPN treatment. Glucose elevates the amylase level in the pancreas, while aminoacidssuppress pancreatic amylase. Aminoacids used as a source of protein maintain normal pancreatic protein levels.

Members of the new heterodimeric aminoacid transporter family are composed of two subunits, a catalytic multitransmembrane spanning protein (light chain) and a type II glycoprotein (heavy chain). These transporters function as exchangers and thereby extend the transmembrane aminoacid transport selectivity to specific aminoacids. The heavy chain rBAT associates with the light chain b degrees (,+)AT to form a cystine and cationic aminoacid transporter. The other heavy chain, 4F2hc, can interact with seven different light chains to form various transporters corresponding to systems L, y(+)L, asc or x(-)(c). The importance of some of these transporters in intestinal and renal (re)absorption of aminoacids is highlighted by the fact that mutations in either the rBAT or b degrees (,+)AT subunit result in cystinuria whereas a defect in the y(+)-LAT1 light chain causes lysinuric protein intolerance. Here we investigated the localization of these transporters in intestine since both diseases are also characterized by altered intestinal aminoacid absorption. Real time PCR showed organ-specific expression patterns for all transporter subunit mRNAs along the intestine and Western blotting confirmed these findings on the protein level. Immunohistochemistry demonstrated basolateral coexpression of 4F2hc, LAT2 and y(+)-LAT1 in stomach and small intestine, whereas rBAT and b degrees (,+)AT were found colocalizing on the apical side of small intestine epithelium. In stomach, 4F2hc and LAT2 were localized in H(+)/K(+)-ATPase-expressing parietal cells. The abundant expression of several members of the heterodimeric transporter family along the murine small intestine suggests their involvement in aminoacids absorption. Furthermore, strong expression of rBAT, b degrees (,+)AT and y(+)-LAT1 in the small intestine explains the reduced intestinal absorption of some aminoacid in patients with cystinuria or lysinuric protein intolerance.

The data here show direct correlations between both the hydrophobicity and the hydrophilicity of the homocodonic aminoacids and their anticodon nucleotides. While the differences between properties of uracil and cytosine derivatives are small, further data show that uracil has an affinity for charged species. Although these data suggest that molecular relationships between aminoacids and anticodons were responsible for the origin of the code, it is not clear what the mechanism of the origin might have been.

The absorption and desorption behaviour of carbon dioxide (CO2) using a composition comprising an ionic compound comprising a cation [A+] and an anion [B-] is described, wherein the anion [B-] is a mono-amine functionalized aminoacid.......The absorption and desorption behaviour of carbon dioxide (CO2) using a composition comprising an ionic compound comprising a cation [A+] and an anion [B-] is described, wherein the anion [B-] is a mono-amine functionalized aminoacid....

Full Text Available In the analysis of plasma aminoacid profile in a group of patients with left ventricular outflow tract pathology (n = 151 increased levels of serine, alanine, arginine, and lysine has been found. These metabolic shifts can be linked with the development of circulatory deficiency and mitochondrial dysfunction. The differentiation of the reference values intervals helps in the assessment of individual aminoacid profiles.

Full Text Available The aminoacid blood pool of children with atopic dermatitis, bronchial asthma, urticaria, angioedema was investigated. The variability of blood plasma aminoacid content (tryptophan, histidine, tyrosine, cysteine, methionine was observed. The changes of histidine and tryptophan levels might be connected with the formation of biogenic amines, such as histamine, serotonine, with take part in the development of allergic reactions and inflammatory processes in organism.

Stereoselective synthesis of unsaturated α-aminoacids was performed by asymmetric alkylation. Two methods were investigated and their enantiomeric excess measured and compared. The first route consisted of an enantioselective approach induced by the Corey-Lygo catalyst under chiral phase transfer conditions while the second one involved the hydroxypinanone chiral auxiliary, both implicating Schiff bases as substrate. In all cases, the use of a prochiral Schiff base gave higher enantiomeric excess and yield in the final desired aminoacid.

Tire producers are increasingly interested in biobased materials, including rubber but also as compounding chemicals. An alternative natural rubber for tire use is produced by guayule, a woody desert shrub native to North America. Alternative compounding chemicals include naturally-occurring amino a...

The last universal common ancestor of contemporary biology (LUCA) used a precise set of 20 aminoacids as a standard alphabet with which to build genetically encoded protein polymers. Considerable evidence indicates that some of these aminoacids were present through nonbiological syntheses prior to the origin of life, while the rest evolved as inventions of early metabolism. However, the same evidence indicates that many alternatives were also available, which highlights the question: what factors led biological evolution on our planet to define its standard alphabet? One possibility is that natural selection favored a set of aminoacids that exhibits clear, nonrandom properties - a set of especially useful building blocks. However, previous analysis that tested whether the standard alphabet comprises aminoacids with unusually high variance in size, charge, and hydrophobicity (properties that govern what protein structures and functions can be constructed) failed to clearly distinguish evolution's choice from a sample of randomly chosen alternatives. Here, we demonstrate unambiguous support for a refined hypothesis: that an optimal set of aminoacids would spread evenly across a broad range of values for each fundamental property. Specifically, we show that the standard set of 20 aminoacids represents the possible spectra of size, charge, and hydrophobicity more broadly and more evenly than can be explained by chance alone.

Full Text Available Aminoacids are important components for peptides and proteins and act as signal transmitters. Only L-aminoacids have been considered necessary in mammals, including humans. However, diverse D-aminoacids, such as D-serine, D-aspartate, D-alanine, and D-cysteine, are found in mammals. Physiological roles of these D-aminoacids not only in the nervous system but also in the endocrine system are being gradually revealed. N-Methyl-D-aspartate (NMDA receptors are associated with learning and memory. D-Serine, D-aspartate, and D-alanine can all bind to NMDA receptors. H2S generated from D-cysteine reduces disulfide bonds in receptors and potentiates their activity. Aberrant receptor activity is related to diseases of the central nervous system (CNS, such as Alzheimer’s disease, amyotrophic lateral sclerosis, and schizophrenia. Furthermore, D-aminoacids are detected in parts of the endocrine system, such as the pineal gland, hypothalamus, pituitary gland, pancreas, adrenal gland, and testis. D-Aspartate is being investigated for the regulation of hormone release from various endocrine organs. Here we focused on recent findings regarding the synthesis and physiological functions of D-aminoacids in the nervous and endocrine systems.

Full Text Available The paper deals with the results of an investigation of the release of selected aminoacids (histidine, tryptophan, tyrosine from model suspensions prepared by co-precipitation with zinc chloride. It has been proven that the influence of the Zn(II/aminoacid molar ratio on dissolution profiles of the tested aminoacids and dissolution half-life (t1/2 of histidine or tryptophan is significant. The amount of aminoacid in the dispersed phase (supporting dose is a determinant of the aminoacid release profile. There is a minimal supporting dose (30.0 μmol of histidine or 17.4 μmol of tryptophan that provides release of similar amounts of aminoacid (4.1–4.6 μmol of histidine or 8.7–9.9 μmol of tryptophan after the same time intervals. The tyrosine release profiles follow first order kinetics since the supporting dose (0.9–11.2 μmol is limited by the tyrosine low solubility in water.

Full Text Available Aminoacid covariation, where the identities of aminoacids at different sequence positions are correlated, is a hallmark of naturally occurring proteins. This covariation can arise from multiple factors, including selective pressures for maintaining protein structure, requirements imposed by a specific function, or from phylogenetic sampling bias. Here we employed flexible backbone computational protein design to quantify the extent to which protein structure has constrained aminoacid covariation for 40 diverse protein domains. We find significant similarities between the aminoacid covariation in alignments of natural protein sequences and sequences optimized for their structures by computational protein design methods. These results indicate that the structural constraints imposed by protein architecture play a dominant role in shaping aminoacid covariation and that computational protein design methods can capture these effects. We also find that the similarity between natural and designed covariation is sensitive to the magnitude and mechanism of backbone flexibility used in computational protein design. Our results thus highlight the necessity of including backbone flexibility to correctly model precise details of correlated aminoacid changes and give insights into the pressures underlying these correlations.

Phytohormone production is one mechanism by which rhizobacteria can stimulate plant growth, but it is not clear whether the bacteria gain from this mechanism. The hypothesis that microbial-derived cytokinin phytohormones stimulate root exudation of aminoacids was tested. The rhizosphere of wheat plants was drenched with the synthetic cytokinin trans-zeatin or inoculated with Bacillus subtilis IB-22 (which produces zeatin type cytokinins) or B. subtilis IB-21 (which failed to accumulate cytokinins). Growing plants in a split root system allowed spatial separation of zeatin application or rhizobacterial inoculation to one compartment and analyses of aminoacid release from roots (rhizodeposition) into the other compartment (without either microbial inoculation or treatment with exogenous hormone). Supplying B. subtilis IB-22 or zeatin to either the whole root system or half of the roots increased concentrations of aminoacids in the soil solution although the magnitude of the increase was greater when whole roots were treated. There was some similarity in aminoacid concentrations induced by either bacterial or zeatin treatment. Thus B. subtilis IB-22 increased aminoacid rhizodeposition, likely due to its ability to produce cytokinins. Furthermore, B. subtilis strain IB-21, which failed to accumulate cytokinins in culture media, did not significantly affect aminoacid concentrations in the wheat rhizosphere. The ability of rhizobacteria to produce cytokinins and thereby stimulate rhizodeposition may be important in enhancing rhizobacterial colonization of the rhizoplane.

Understanding how codons became associated with their specific aminoacids is fundamental to deriving a theory for the origin of the genetic code. Carl Woese and coworkers designed a series of experiments to test associations between aminoacids and nucleobases that may have played a role in establishing the genetic code. Through these experiments it was found that a property of aminoacids called the polar requirement (PR) is correlated with the organization of the codon table. No other property of aminoacids has been found that correlates with the codon table as well as PR, indicating that PR is uniquely related to the modern genetic code. Using molecular dynamics simulations of aminoacids in solutions of water and dimethylpyridine used to experimentally measure PR, we show that variations in the partitioning between the two phases as described by radial distribution functions correlate well with the measured PRs. Partition coefficients based on probability densities of the aminoacids in each phase have the linear behavior with base concentration as suggested by PR experiments.

In this work,we make an investigation on the preferences of orientations between aminoacids using the orientation defined based on the local geometry of the aminoacids concerned.It is found that there are common preferences of orientations (70°,30°,140°) and (110°,340°,100°) for various pairs of aminoacids.Different side chains may strengthen or weaken the common preferences,which is related to the effect of packing.Some aminoacids having specific local flexibility may possess some preferences of orientations besides the common ones,such as (10°,280°,210°) .Another analysis on the pairs of the aminoacids with different secondary-structure preferences shows that the directional interaction may affect the distribution of orientation more effectively than the packing or local flexibility.All these results provide us some insight of the organization of aminoacids in protein,and their relation with some related interactions.

Ureilites are a class of meteorites that lack chondrules (achondrites) but have relatively high carbon abundances, averaging approx.3 wt %. Using highly sensitive liquid chromatography coupled with UV fluorescence and time-of-flight mass spectrometry (LC-FD/ToF-MS), it was recently determined that there are aminoacids in. fragment 94 of the Almahata Sitta ureilite[l]. Based on the presence of aminoacids that are rare in the Earth's biosphere, as well as the near-racemic enantiomeric ratios of marry of the more common aminoacids, it was concluded that most of the detected aminoacids were indigenous to the meteorite. Although the composition of the Almahata Sitta ureilite appears to be unlike other recovered ureilites, the discovery of aminoacids in this meteorite raises the question of whether other ureilites rnav also contain aminoacids. Herein we present the results of LC-FDlTo.F-MS analyses of: a sand sample from the Almahata Sitta strewn held, Almahata Sitta fragments 425 (an ordinary H5 chondrite) and 427 (ureilite), as well as an Antarctic ureilite (Allan lulls, ALHA 77257).

Often referred to as the "building blocks of proteins", the 20 canonical proteinogenic aminoacids are ubiquitous in biological systems as the functional units in proteins. Sometimes overlooked are their varying additional roles that include serving as metabolic intermediaries, playing structural roles in bioactive natural products, acting as cosubstrates in enzymatic transformations, and as key regulators of cellular physiology. Aminoacids can also serve as biological sources of both carbon and nitrogen and are found in the rhizosphere as a result of lysis or cellular efflux from plants and microbes and proteolysis of existing peptides. While both plants and microbes apparently prefer to take up nitrogen in its inorganic form, their ability to take up and use aminoacids may confer a selective advantage in certain environments where organic nitrogen is abundant. Further, certain aminoacids (e.g., glutamate and proline) and their betaines (e.g., glycine betaine) serve as compatible solutes necessary for osmoregulation in plants and microbes and can undergo rapid cellular flux. This ability is of particular importance in an ecological niche such as the rhizosphere, which is prone to significant variations in solute concentrations. Aminoacids are also shown to alter key phenotypes related to plant root growth and microbial colonization, symbiotic interactions, and pathogenesis in the rhizosphere. This review will focus on the sources, transport mechanisms, and potential roles of the 20 canonical proteinogenic aminoacids in the rhizosphere.

Aminoacid catabolism in Thermococcales is presumed to proceed via three steps: oxidative deamination of aminoacids by glutamate dehydrogenase (GDH) or aminotransferases, oxidative decarboxylation by 2-oxoacid:ferredoxin oxidoreductases (KOR), and hydrolysis of acyl-coenzyme A (CoA) by ADP-forming acyl-CoA synthetases (ACS). Here, we performed a genetic examination of enzymes involved in Glu catabolism in Thermococcus kodakarensis. Examination of aminoacid dehydrogenase activities in cell extracts of T. kodakarensis KUW1 (ΔpyrF ΔtrpE) revealed high NADP-dependent GDH activity, along with lower levels of NAD-dependent activity. NADP-dependent activities toward Gln/Ala/Val/Cys and an NAD-dependent threonine dehydrogenase activity were also detected. In KGDH1, a gene disruption strain of T. kodakarensis GDH (Tk-GDH), only threonine dehydrogenase activity was detected, indicating that all other activities were dependent on Tk-GDH. KGDH1 could not grow in a medium in which growth was dependent on aminoacid catabolism, implying that Tk-GDH is the only enzyme that can discharge the electrons (to NADP(+)/NAD(+)) released from aminoacids in their oxidation to 2-oxoacids. In a medium containing excess pyruvate, KGDH1 displayed normal growth, but higher degrees of aminoacid catabolism were observed compared to those for KUW1, suggesting that Tk-GDH functions to suppressaminoacid oxidation and plays an anabolic role under this condition. We further constructed disruption strains of 2-oxoglutarate:ferredoxin oxidoreductase and succinyl-CoA synthetase. The two strains displayed growth defects in both media compared to KUW1. Succinate generation was not observed in these strains, indicating that the two enzymes are solely responsible for Glu catabolism among the multiple KOR and ACS enzymes in T. kodakarensis.

Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected aminoacid synthesis. Here, using a supercritical CO2/liquid H2O (10:1) system which mimicked crust soda fountains, we demonstrate production of aminoacids from hydroxylamine (nitrogen source) and keto acids (oxylic acid sources). In this research...

The ratios of d- versus l-aminoacids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which aminoacids in sedimentary organic matter racemize abiotically between the d- and the l-forms. Based on a heating experiment, we report kinetic parameters for racemization of aspartic acid, glutamic acid, serine, and alanine in bulk sediment from Aarhus Bay, Denmark, taken from the surface, 30 cm, and 340 cm depth be...

As one of general anesthetics, propofol, has been used for surgical procedures of visceral organs. However, the mechanisms underlying the action of propofol on visceral nociception remain controversial. The aim of this study is to test whether the antinociception of systemic administration of propofol against visceral stimuli is related to the changes in release of excitatory and inhibitory aminoacids in the spinal cord. The spinal microdialysis catheters were implanted subarachnoidally via the atlanto-occipital membrane in healthy SD rats. The rats received an intraperitoneal injection of acetic acid for visceral pain induction 10min after intraperitoneal pretreatment with vehicle or propofol (100mg/kg). The acetic acid-induced writhing assay was used to determine the degree of antinociception. Cerebrospinal fluid dialysate was collected by microdialysis from the spinal subarachnoid space before pretreatment and after visceral pain induction. Visceral pain-induced release of aminoacids into the dialysate, including glutamate, aspartate, and γ-amino butyric acid was evaluated by measuring the changes in the concentrations of these aminoacids. Acetic acid increased release of aspartate and glutamate, and decreased release of γ-amino butyric acid in the cerebrospinal fluid as measured by microdialysis. Pretreatment with propofol significantly decreased writhing responses induced by visceral pain, suppressed the visceral pain-induced aspartate and glutamate release, and reversed the decreased release of γ-amino butyric acid in the cerebrospinal fluid. These data provide evidence for a potential mechanism for the antinociceptive effects of propofol on visceral nociception. 2010 Elsevier Ireland Ltd. All rights reserved.

To determine values for the digestible indispensable aminoacid score (DIAAS), it is recommended that ileal aminoacid (AA) digestibility values obtained in growing pigs are used to characterise protein quality in different foods. Therefore, an experiment was conducted to determine the standardised ileal digestibility (SID) of AA in eight cereal grains (yellow dent maize, Nutridense maize, dehulled barley, dehulled oats, polished white rice, rye, sorghum and wheat) fed to pigs, where SID values in pigs can be used to calculate approximate DIAAS values in humans. In the present experiment, twenty-four barrows with a T-cannula inserted in the distal ileum were allotted to eight diets and fed for three periods to give a total of nine replicate pigs per diet. Each period lasted 14 d, and ileal digesta samples were collected on days 13 and 14. Among the SID values obtained for all cereal grains, values for total indispensable AA were greatest (P

the 13C spin-lattice relaxation. Atlast, MgCl2 is proposed as an efficient relaxation agent for analysis of aminoacids and some carboxylic acids.Samples were dissolved with the aid of supersonic which has the effect of degassing, and they were degassed again with supersonic for 30 seconds right before determination. All of the 13C NMR was obtained with a Bruker DPX-300 NMR instrument, using NOE-suppressed inverse gated decoupling with a recycle delay 8.00s and a sweep width 30120.48Hz, experiment temperature is integral of the carbon with the smallest chemical shift is calibrated as 10.00. Spin-lattice relaxation times (T1's) were determined by using inversion recovery according to Bruker avance user's guide.The pulse sequence is (T-90.°-T-180°-o-90t°) n.

The ratios of d- versus l-aminoacids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which aminoacids in sedimentary organic matter racemize abiotically between the d- and the l-forms. Based on a heating experiment, we report kinetic parameters for racemization of aspartic acid, glutamic acid, serine, and alanine in bulk sediment from Aarhus Bay, Denmark, taken from the surface, 30 cm, and 340 cm depth below seafloor. Extrapolation to a typical cold deep sea sediment temperature of 3°C suggests racemization rate constants of 0.50×10(-5)-11×10(-5) yr(-1). These results can be used in conjunction with measurements of sediment age to predict the ratio of d:l aminoacids due solely to abiotic racemization of the source material, deviations from which can indicate the abundance and turnover of active microbial populations.

Aminoacids that carry charges on their side groups can bind to double stranded DNA (dsDNA) and change the strength of the double helix. Measurement of the DNA melting temperature (Tm) confirmed that acidicaminoacids (Glu, Asp) weaken the H-bonds between DNA strands, whereas basic aminoacids (Arg, Lys) strengthen the interaction between the strands. A rank correlation exists between the aminoacid isoelectric points and the observed changes in Tm. A similar dependence of the hyperchromic effect on the isoelectric point of a protein (pepsin, insulin, cortexin, and protamine) was observed for DNA-protein complexes at room temperature. Short peptides (KE, AEDG, and KEDP) containing a mixture of acidic and basic aminoacid residues also affect Tm and the stability of the double helix. A model for binding Glu and Lys to dsDNA was explored by a docking simulation. The model shows that Glu, in an untwisted shape, binds to dsDNA in its major groove and disrupts three H-bonds between the strands, thereby destabilizing the double helix. Lys, in an untwisted shape, binds to the external side of the dsDNA and forms two bonds with O atoms of neighboring phosphodiester groups, thereby strengthening the DNA helix.

Aminoacids are the basic "building blocks" that combine to form proteins and play an important physiological role in all life-forms. Aminoacids can be used as models for the examination of the importance of intermolecular bonding in life processes. Raman spectra serve to obtain information regarding molecular conformation, giving valuable insights into the topology of more complex molecules (peptides and proteins). In this paper, aminoacids and their aqueous solution have been studied by Raman spectroscopy. Comparisons of certain values for these frequencies in aminoacids and their aqueous solutions are given. Spectra of solids when compared to those of the solute in solution are invariably much more complex and almost always sharper. We present a collection of Raman spectra of 18 kinds of aminoacids ( L-alanine, L-arginine, L-aspartic acid, cystine, L-glutamic acid, L-glycine, L-histidine, L-isoluecine, L-leucine, L-lysine, L-phenylalanine, L-methionone, L-proline, L-serine, L-threonine, L-tryptophan, L-tyrosine, L-valine) and their aqueous solutions that can serve as references for the interpretation of Raman spectra of proteins and biological materials.

Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of aminoacids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several aminoacids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein aminoacids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of aminoacid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for aminoacid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of aminoacid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of aminoacids.

Full Text Available The coupling reaction of benzoic acid and nicotinic acid hydrazides with N- protected L-aminoacids including valine, leucine, phenylalanine, glutamic acid and tyrosine is reported. The target compounds, N-Boc-aminoacid-(N`-benzoyl- and N- Boc-aminoacid-(N`-nicotinoyl hydrazides 5a-5e and 6a-6e were prepared in very high yields and purity using N-[(dimethylamino-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl- methylene]-N-methyl-methanaminium hexafluorophosphate N-oxide (HATU as coupling reagent. The antimicrobial activity of the Cu and Cd complexes of the designed compounds was tested. The products were deprotected affording the corresponding aminoacid-(N`-benzoyl hydrazide hydrochloride salts (7a-7e and aminoacid-(N`- nicotinoyl hydrazide hydrochloride salts (8a-8e. These compounds and their Cu and Cd complexes were also tested for their antimicrobial activity. Several compounds showed comparable activity to that of ampicillin against S. aureus and E. coli.

. To identify agonists at this orphan receptor, we faced the challenges of achieving surface expression in mammalian cell lines and establishing an appropriate functional assay. Generating a chimeric receptor construct, h6A/5.24, containing the ligand binding amino-terminal domain (ATD) of hGPRC6A...... and was employed to rationally select potential ligands. Measurement of Ca2+-dependent chloride currents in Xenopus laevis oocytes facilitated the deorphanization of h6A/5.24 and identification of L-alpha-aminoacids as agonists. The most active agonists were basic L-alpha-aminoacids, L-Arg, L-Lys, and L...

At two sites in the Armenhof district, 10 km east of Fulda, Germany, dew samples were collected from June 1996 to June 1997 and investigated for free and protein-bound aminoacids. On account of the high pollen content, at the beginning of June 1996 and in May 1997 total aminoacid concentrations were 53-390 μmol l -1, in one sample 922 μmol l -1. At other times the concentration in dew was 8-164 μmol l -1. On 4 and 5 June 1996 the diluted free aminoacid fraction (DFAA) of the total hydrolysed aminoacids (THAA) at both sites amounted to 35-44% and was predominantly arginine, proline and glutamine/glutamate. Likewise on 11 March 1997 the fraction of DFAA was found to be 39.5% with extremely high arginine and proline fractions. At other times the DFAA-fraction was in the range 14-26%. From July 1996 to June 1997 the aminoacid concentrations in the vapours rising from a meadow were also measured and it ranged from 8 to 51 μmol l -1. From July to October 1996 the aminoacid composition in the hydrolysates of dew samples and meadow vapours collected overnight were almost identical. The DFAA fraction in the condensation water collected overnight from the meadow varied from 18 to 40%. From 4 to 6 June 1996, on 11 and 13 March 1997 and in the period 16-20 May 1997, the aminoacid distribution in dew showed much variation. The percentage fraction of arginine and proline in the hydrolysate increased greatly, whereas that of glycine and serine decreased. The large increase in proline and arginine in hydrolysate is attributable solely to the large amounts of free arginine and proline. This effect occurred in both 1996 and 1997 over several days at both sites at any one time and therefore appears confirmed.

Feline dysautonomia (FD) is a multiple system neuropathy of unknown aetiology. An apparently identical disease occurs in horses (equine grass sickness, EGS), dogs, rabbits, hares, sheep, alpacas and llamas. Horses with acute EGS have a marked reduction in plasma concentrations of the sulphur aminoacids (SAA) cyst(e)ine and methionine, which may reflect exposure to a neurotoxic xenobiotic. The aim of this study was to determine whether FD cats have alterations in aminoacid profiles similar to those of EGS horses. Aminoacids were quantified in plasma/serum from 14 FD cats, 5 healthy in-contact cats which shared housing and diet with the FD cats, and 6 healthy control cats which were housed separately from FD cats and which received a different diet. The adequacy of aminoacids in the cats' diet was assessed by determining the aminoacid content of tinned and dry pelleted foods collected immediately after occurrences of FD. Compared with controls, FD cats had increased concentrations of many essential aminoacids, with the exception of methionine which was significantly reduced, and reductions in most non-essential aminoacids. In-contact cats also had inadequate methionine status. Artefactual loss of cysteine during analysis precluded assessment of the cyst(e)ine status. Food analysis indicated that the low methionine status was unlikely to be attributable to dietary inadequacy of methionine or cystine. Multi-mycotoxin screening identified low concentrations of several mycotoxins in dry food from all 3 premises. While this indicates fungal contamination of the food, none of these mycotoxins appears to induce the specific clinico-pathologic features which characterise FD and equivalent multiple system neuropathies in other species. Instead, we hypothesise that ingestion of another, as yet unidentified, dietary neurotoxic mycotoxin or xenobiotic, may cause both the characteristic disease pathology and the plasma SAA depletion.

Feline dysautonomia (FD) is a multiple system neuropathy of unknown aetiology. An apparently identical disease occurs in horses (equine grass sickness, EGS), dogs, rabbits, hares, sheep, alpacas and llamas. Horses with acute EGS have a marked reduction in plasma concentrations of the sulphur aminoacids (SAA) cyst(e)ine and methionine, which may reflect exposure to a neurotoxic xenobiotic. The aim of this study was to determine whether FD cats have alterations in aminoacid profiles similar to those of EGS horses. Aminoacids were quantified in plasma/serum from 14 FD cats, 5 healthy in-contact cats which shared housing and diet with the FD cats, and 6 healthy control cats which were housed separately from FD cats and which received a different diet. The adequacy of aminoacids in the cats’ diet was assessed by determining the aminoacid content of tinned and dry pelleted foods collected immediately after occurrences of FD. Compared with controls, FD cats had increased concentrations of many essential aminoacids, with the exception of methionine which was significantly reduced, and reductions in most non-essential aminoacids. In-contact cats also had inadequate methionine status. Artefactual loss of cysteine during analysis precluded assessment of the cyst(e)ine status. Food analysis indicated that the low methionine status was unlikely to be attributable to dietary inadequacy of methionine or cystine. Multi-mycotoxin screening identified low concentrations of several mycotoxins in dry food from all 3 premises. While this indicates fungal contamination of the food, none of these mycotoxins appears to induce the specific clinico-pathologic features which characterise FD and equivalent multiple system neuropathies in other species. Instead, we hypothesise that ingestion of another, as yet unidentified, dietary neurotoxic mycotoxin or xenobiotic, may cause both the characteristic disease pathology and the plasma SAA depletion. PMID:28333983

Like mammals, insects need to ingest proteins from foods because they cannot synthesise several aminoacids. Aminoacids are also essential nutrients for Drosophila melanogaster, especially for female egg production, but how flies detect aminoacids and how the feeding response to aminoacids is regulated are unknown. In this study, the two-choice preference test, the proboscis extension reflex test and a CAFE assay were performed to explore the ability of D. melanogaster to detect and discriminate aminoacids. To determine whether D. melanogaster change their feeding preference to aminoacids after being deprived of them, as previously reported in the locust, two groups of flies raised on the usual medium or on glucose medium were compared. Amino-acid-deprived flies demonstrated enhanced preference to an aminoacid mixture and to several aminoacids. These flies ingested aminoacids even when they were replete with glucose. The proboscis extension reflex to particular aminoacids was induced only in amino-acid-deprived flies. Our findings indicate that the sensitivity of labellar taste cells to aminoacids may change when flies are deficient in aminoacid supply, and also reveal that the detection pathways for individual aminoacids may differ. We suggest the existence of an aminoacid receptor and a monitoring system regulating the feeding responses to aminoacids.

Full Text Available Normal in vitro thyroid peroxidase (TPO iodide oxidation activity was completely inhibited by a hydrolyzed TPO preparation (0.15 mg/ml or hydrolyzed bovine serum albumin (BSA, 0.2 mg/ml. A pancreatic hydrolysate of casein (trypticase peptone, 0.1 mg/ml and some aminoacids (cysteine, tryptophan and methionine, 50 µM each also inhibited the TPO iodide oxidation reaction completely, whereas casamino acids (0.1 mg/ml, and tyrosine, phenylalanine and histidine (50 µM each inhibited the TPO reaction by 54% or less. A pancreatic digest of gelatin (0.1 mg/ml or any other aminoacid (50 µM tested did not significantly decrease TPO activity. The aminoacids that impair iodide oxidation also inhibit the TPO albumin iodination activity. The inhibitory aminoacids contain side chains with either sulfur atoms (cysteine and methionine or aromatic rings (tyrosine, tryptophan, histidine and phenylalanine. Among the aminoacids tested, only cysteine affected the TPO guaiacol oxidation reaction, producing a transient inhibition at 25 or 50 µM. The iodide oxidation inhibitory activity of cysteine, methionine and tryptophan was reversed by increasing iodide concentrations from 12 to 18 mM, while no such effect was observed when the cofactor (H2O2 concentration was increased. The inhibitory substances might interfere with the enzyme activity by competing with its normal substrates for their binding sites, binding to the free substrates or reducing their oxidized form.

We investigated the hypothesis that essential aminoacids are being replaced in proteins by non-essential aminoacids.We compared the aminoacid composition in human, worm and fly proteomes, organisms that cannot synthesize all aminoacids, with the aminoacids of the proteomes of plant, bakers yeast and budding yeast, which are capable of synthesizing them. The analysis covered 460,737 proteins (212,197,907 aminoacids). The data suggest a bias towards the usage of non-essential ami...

, glutamic acid, and arginine, respectively. The aminoacid score of the nine algae varied from 44% to 92%, the most commonly first limiting aminoacid being histidine. Lutein, β-carotene, and zeaxanthin were the identified carotenoids. Contents of all macro and trace minerals, with the exception...

, glutamic acid, and arginine, respectively. The aminoacid score of the nine algae varied from 44% to 92%, the most commonly first limiting aminoacid being histidine. Lutein, β-carotene, and zeaxanthin were the identified carotenoids. Contents of all macro and trace minerals, with the exception...

An effective and improved procedure is developed for the synthesis of α-hydroxy carboxylic acids by treatment of the corresponding protonated α-aminoacid with tert-butyl nitrite in 1,4-dioxane-water. The amino moiety must be protonated and located α to a carboxylic acid function in order...

Aminoacid analysis is among the most accurate methods for absolute quantification of proteins and peptides. Here, we combine acid hydrolysis with the addition of isotopically labeled standard aminoacids and analysis by mass spectrometry for accurate and sensitive protein quantitation...

The intradialytic losses into the dialysate of free aminoacids (AA) and alpha-amino nitrogen were determined during the dialysis of three children. Variations in plasma AA were determined pre- and postdialysis. The effect of these losses with the addition of an Abbott General AminoAcid Mixture to the dialysate in concentrations of 8.5, 17, and 34 mg/100 ml was studied. The major determinant of AA losses was the plasma concentration of the AA before beginning the dialysis treatment. Dialysance of individual AA varied inversely with their molecular weights. A zero flux of alpha-amino nitrogen occurred at a derived concentration of 22 mg/100 ml of the AA additive in the dialysate. Plasma concentrations of nonessential aminoacids were little affected by the dialysate additive. In contrast, total essential aminoacid nitrogen which fell during baseline dialyses showed significant improvement when the AA solution was added to the dialysate. This study suggests that the addition of AA to the dialysate bath may be effective in decreasing AA nitrogen losses during dialysis.

A number of nutrient sensing seven trans-membrane (7TM) receptors have been identified and characterized over the past few years. While the sensing mechanisms to carbohydrates and free fatty acids are well understood, the molecular basis of aminoacid sensing has recently come to the limelight. T....... The present review describes the current status of promiscuous L-α-aminoacid sensors, the calcium sensing receptor (CaSR), the GPRC6A receptor, the T1R1/T1R3 receptor and also their molecular pharmacology, expression pattern and physiological significance....

The presence of non-protein alpha-dialkyl-aminoacids such as alpha-aminoisobutyric acid (alpha-A1B) and isovaline (Iva), which are relatively rare in the terrestrial biosphere, has long been used as an indication of the indigeneity of meteoritic aminoacids, however, the discovery of alpha-AIB in peptides producers by a widespread group of filamentous fungi indicates the possibility of a terrestrial biotic source for the alpha-AIB observed in some meteorites. The alpha-AIB-containing peptides produced by these fungi are dubbed peptaibiotics. We measured the molecular distribution and stable carbon and nitrogen isotopic ratios for aminoacids found in the total hydrolysates of four biologically synthesized peptaibiotics. We compared these aneasurenetts with those from the CM2 carbonaceous chondrite Murchison and from three Antarctic CR2 carbonaceous chondrites in order to understand the peptaibiotics as a potential source of meteoritic contamination.

In our previous report, it was discovered that the polycondensation of 9-amino-nonanoic acid follows second order from the beginning up to the extent of reaction, p, around 99%, and after which the reaction changes rapidly to third order. In this paper, we wish to report that this change of the reaction order from second to third occurred also in the polycondensation of 6aminocaproic acid and 11-amino-undecanoic acid. The transition region lay again at p around 99%.It may be concluded that this is a general rule in the polycondensation of the ω-amino-acids (monomers of the A-B type), and the controversial results that appeared in the literature may be cleared up by our experiments.

The complete aminoacid sequence of the cytotoxin mitogillin has been determined by sequencing the intact chain and peptide fragments produced by cleavage at methionyl, arginyl, lysyl, and tryptophanyl residues and at one aspartic acid-proline bond. The protein consists of 149 aminoacid residues with alanine at the NH/sub 2/ terminus and histidine at the COOH terminus. The calculated Mr of the native mitogillin was 16,867. The native molecule presents two disulfide bridges, one between cysteine residues at positions 5 and 147 and another one between cysteine residues at positions 75 and 131. The aminoacid sequence of mitogillin shows 86% homology with another cytotoxic protein called alpha-sarcin.

4-Fluoroisoleucine was produced by ammonolysis of 2-bromo-4-fluoro-3-methylpentanoic acid, which resulted from the bromofluorination of 4-methyl-2-pentenoic acid. It did not inhibit Plasmodium berghei in mice at 640 mg/kg and was not toxic to the animals. The fluoroamino acid inhibited Aspergillus niger, Trichoderma viride, Myrothecium verrucaria, Trichophyton mentagrophytes, and Mucor mucedo in Czapek solution agar at a concentration between 10(4) and 10(3) microgram/ml. Growth of Escherichia coli was inhibited 25% at 900 microgram/ml in a defined medium.

Full Text Available The “RNA world” hypothesis is seen as one of the main contenders for a viable theory on the origin of life. Relatively small RNAs have catalytic power, RNA is everywhere in present-day life, the ribosome is seen as a ribozyme, and rRNA and tRNA are crucial for modern protein synthesis. However, this view is incomplete at best. The modern protein-RNA ribosome most probably is not a distorted form of a “pure RNA ribosome” evolution started out with. Though the oldest center of the ribosome seems “RNA only”, we cannot conclude from this that it ever functioned in an environment without aminoacids and/or peptides. Very small RNAs (versatile and stable due to basepairing and aminoacids, as well as dipeptides, coevolved. Remember, it is the amino group of aminoacylated tRNA that attacks peptidyl-tRNA, destroying the bond between peptide and tRNA. This activity of the aminoacid part of aminoacyl-tRNA illustrates the centrality of aminoacids in life. With the rise of the “RNA world” view of early life, the pendulum seems to have swung too much towards the ribozymatic part of early biochemistry. The necessary presence and activity of aminoacids and peptides is in need of highlighting. In this article, we try to bring the role of the peptide component of early life back into focus. We argue that an RNA world completely independent of aminoacids never existed.

Aminoacid containing glass-ionomer cements were synthesized, formulated, and evaluated for orthopedic application. The formulation of different aminoacid containing glass-ionomer bone cements was optimized, and conventional and resin-modified glass-ionomer bone cements were compared. Properties of interest included handling characteristics, physical and chemical properties, and mechanical strength of the bone cement. The study was based on the synthesis of different vinyl containing aminoacids, different polyelectrolytes containing these aminoacid residues, and different resin-modified polyelectrolytes, as well as formulation and evaluation of conventional and resin-modified glass-ionomer bone cements using these polyelectrolytes. Systematic preparation of polyelectrolytes and formulation of glass-ionomer bone cements were essential features of this work, since we anticipated that the mechanical properties of the glass-ionomer bone cements could be strongly affected by the nature of the polyelectrolytes and formulation. Mechanical properties were evaluated in a screw driven mechanical testing machine, and structure-property relationships were determined by scanning electron microscopic (SEM) observation of the fracture surface of the specimens. How the structure of polyelectrolytes, such as different aminoacid residues, molecular weight, different modifying resin, and formulation of glass-ionomer bone cement, affected the mechanical properties was also studied.

Full Text Available Nitrogen is an essential mineral nutrient and it is often transported within living organisms in its reduced form, as aminoacids. Transport of aminoacids across cellular membranes requires proteins, and here we report the phylogenetic analysis across taxa of two aminoacid transporter families, the AminoAcid Permeases (AAPs and the Lysine-Histidine-like Transporters (LHTs. We found that the two transporter families form two distinct groups in plants supporting the concept that both are essential. AAP transporters seem to be restricted to land plants. They were found in Selaginella moellindorffii and Physcomitrella patens but not in Chlorophyte, Charophyte or Rhodophyte algae. AAPs were strongly represented in vascular plants, consistent with their major function in phloem (vascular tissue loading of aminoacids for sink nitrogen supply. LHTs on the other hand appeared prior to land plants. LHTs were not found in chlorophyte algae Chlamydomonas reinhardtii and Volvox carterii. However, the characean alga Klebsormidium flaccidum encodes KfLHT13 and phylogenetic analysis indicates that it is basal to land plant LHTs. This is consistent with the hypothesis that characean algae are ancestral to land plants. LHTs were also found in both Selaginella moellindorffii and Physcomitrella patens as well as in monocots and eudicots. To date, AAPs and LHTs have mainly been characterized in Arabidopsis (eudicots and these studies provide clues to the functions of the newly identified homologs.

Cultural heritage parchments made from the reticular dermis of animals have been subject to studies of deterioration and conservation by aminoacid analysis. The reticular dermis contains a varying mixture of collagen I and III (COL I and III). When dealing with the results of the aminoacid analyses, till now the COL III content has not been taken into account. Based on the available aminoacid sequences, we present a method for determining the amount of COL III in the reticular dermis of new and historical parchments calculated from the ratio of Ile/Val. We find COL III contents between 7 and 32 % in new parchments and between 0.2 and 40 % in the historical parchments. This is consistent with results in the literature. The varying content of COL III has a significant influence on the uncertainty of the aminoacid analysis. Although we have not found a simple correlation between the COL III content and the degree of deterioration, our results show that this question must be taken into consideration in future studies of the chemical and physical deterioration of parchment measured by aminoacid analysis and other analytical methods.

Residue-specific incorporation of non-canonical aminoacids into proteins is usually performed in vivo using aminoacid auxotrophic strains and replacing the natural aminoacid with an unnatural aminoacid analog. Herein, we present an efficient aminoacid depleted cell-free protein synthesis system that can be used to study residue-specific replacement of a natural aminoacid by an unnatural aminoacid analog. This system combines a simple methodology and high protein expression titers with a high-efficiency analog substitution into a target protein. To demonstrate the productivity and efficacy of a cell-free synthesis system for residue-specific incorporation of unnatural aminoacids in vitro, we use this system to show that 5-fluorotryptophan and 6-fluorotryptophan substituted streptavidin retain the ability to bind biotin despite protein-wide replacement of a natural aminoacid for the aminoacid analog. We envisage this aminoacid depleted cell-free synthesis system being an economical and convenient format for the high-throughput screening of a myriad of aminoacid analogs with a variety of protein targets for the study and functional characterization of proteins substituted with unnatural aminoacids when compared to the currently employed in vivo methodologies.

In the 1950s Corynebacterium glutamicum was found to be a very efficient producer of L-glutamic acid. Since this time biotechnological processes with bacteria of the species Corynebacterium developed to be among the most important in terms of tonnage and economical value. L-Glutamic acid and L-lysine are bulk products nowadays. L-Valine, L-isoleucine, L-threonine, L-aspartic acid and L-alanine are among other aminoacids produced by Corynebacteria. Applications range from feed to food and pharmaceutical products. The growing market for aminoacids produced with Corynebacteria led to significant improvements in bioprocess and downstream technology as well as in molecular biology. During the last decade big efforts were made to increase the productivity and to decrease the production costs. This review gives an overview of the world market for aminoacids produced by Corynebacteria. Significant improvements in bioprocess technology, i.e. repeated fed batch or continuous production are summarised. Bioprocess technology itself was improved furthermore by application of more sophisticated feeding and automatisation strategies. Even though several aminoacids developed towards commodities in the last decade, side aspects of the production process like sterility or detection of contaminants still have increasing relevance. Finally one focus of this review is on recent developments in downstream technology.

Short-chain fatty acids (SCFA) originate mainly in the colon through bacterial fermentation of polysaccharides. To test the hypothesis that SCFA may originate from polypeptides as well, the production of these acids from albumin and specific aminoacids was examined in a faecal incubation system....... Albumin was converted to all C2-C5-fatty acids, whereas aminoacids generally were converted to specific SCFA, most often through the combination of a deamination and decarboxylation of the aminoacids, although more complex processes also took place. This study indicates that a part of the intestinal...

Stevia, a non-caloric natural sweetener with beneficial properties and considerable antioxidants and aminoacids, is increasingly consumed as an infusion. This work evaluates the influence of the conditions (temperature: 50, 70 or 90 °C and time: 1, 5, 20 or 40 min) applied to obtain Stevia infusions, on antioxidants (total phenols, flavonoids and antioxidant activity) and aminoacids. The total concentration of the eleven aminoacids found was 11.70 mg/g in dried leaves and from 6.84 to 9.11 mg/g per gram of Stevia in infusions. However, infusions showed higher levels of certain aminoacids (alanine, asparagine, leucine and proline), and greater values of the three antioxidant parameters in comparison with dry leaves. Temperature had more influence (minimum values at 50 °C and maximum at 90 °C) than time in the case of antioxidants. At 90 °C there were no important increases in the extraction of antioxidant compounds after 5 min; each gram of Stevia had 117 mg trolox (total antioxidant activity), 90 mg gallic acid (total phenols) and 56 mg catechin equivalents (flavonoids). Varying the temperature and time conditions no notable differences were observed in the concentrations of the majority of aminoacids. However, the infusion treatment at 90 °C for 5 min was the best, as it gave the highest yield of 8 of the 11 aminoacids. Therefore, with respect to the compounds analyzed in this study, the best way to obtain Stevia leaf infusions is the same as the domestic process, almost boiling water for a short time.

Oxidative decarboxylation and transamination of 1-/sup 14/C-branched chain amino and alpha-keto acids were examined in mitochondria isolated from rat heart. Transamination was inhibited by aminooxyacetate, but not by L-cycloserine. At equimolar concentrations of alpha-ketoiso(1-/sup 14/C)valerate (KIV) and isoleucine, transamination was increased by disrupting the mitochondria with detergent which suggests transport may be one factor affecting the rate of transamination. Next, the subcellular distribution of the aminotransferase(s) was determined. Branched chain aminotransferase activity was measured using two concentrations of isoleucine as amino donor and (1-/sup 14/C)KIV as amino acceptor. The data show that branched chain aminotransferase activity is located exclusively in the mitochondria in rat heart. Metabolism of extramitochondrial branched chain alpha-keto acids was examined using 20 microM (1-/sup 14/C)KIV and alpha-ketoiso(1-/sup 14/C)caproate (KIC). There was rapid uptake and oxidation of labeled branched chain alpha-keto acid, and, regardless of the experimental condition, greater than 90% of the labeled keto acid substrate was metabolized during the 20-min incubation. When a branched chain aminoacid (200 microM) or glutamate (5 mM) was present, 30-40% of the labeled keto acid was transaminated while the remainder was oxidized. Provision of an alternate amino acceptor in the form of alpha-keto-glutarate (0.5 mM) decreased transamination of the labeled KIV or KIC and increased oxidation. Metabolism of intramitochondrially generated branched chain alpha-keto acids was studied using (1-/sup 14/C)leucine and (1-/sup 14/C)valine. Essentially all of the labeled branched chain alpha-keto acid produced by transamination of (1-/sup 14/C)leucine or (1-/sup 14/C)valine with a low concentration of unlabeled branched chain alpha-keto acid (20 microM) was oxidized.

Full Text Available This report describes a partial aminoacid sequences from three putative outer envelope proteins from Leptospira serovar pomona. In order to obtain internal fragments for protein sequencing, enzymatic and chemical digestion was performed. The enzyme clostripain was used to digest the proteins 32 and 45 kDa. In situ digestion of 40 kDa molecular weight protein was accomplished using cyanogen bromide. The 32 kDa protein generated two fragments, one of 21 kDa and another of 10 kDa that yielded five residues. A fragment of 24 kDa that yielded nineteen residues of aminoacids was obtained from 45 kDa protein. A fragment with a molecular weight of 20 kDa, yielding a twenty aminoacids sequence from the 40 kDa protein.

Molecularly imprinted polymers provide an alternative to traditional methods of aminoacid analysis. The imprinted polymers are more robust and significantly less expensive than, for example, ELISA analysis. Aminoacid imprinted nylon-6 thin films were studied by differential scanning calorimetry and scanning electron microscopy. Endothermic peaks were observed for imprinted films at temperatures higher than that for pure nylon, indicating the formation of a more-ordered, hydrogen bonded polymer. Removal of the aminoacid from the imprinted film resulted in reversion to the peak observed for pure nylon-6. Additives, β-cyclodextrin and multiwalled carbon nanotubes, were added to the imprinted polymer solutions as a means to increase the porosity of the films. These studies resulted in alternative morphologies and calorimetric results that provide additional functionalities and applications for imprinted polymers.

The role of tRNA in translating the genetic code has received considerable attention over the last 50 years, and we now know in great detail how particular aminoacids are specifically selected and brought to the ribosome in response to the corresponding mRNA codon. Over the same period, it has...... also become increasingly clear that the ribosome is not the only destination to which tRNAs deliver aminoacids, with processes ranging from lipid modification to antibiotic biosynthesis all using aminoacyl-tRNAs as substrates. Here we review examples of alternative functions for tRNA beyond...... translation, which together suggest that the role of tRNA is to deliver aminoacids for a variety of processes that includes, but is not limited to, protein synthesis....

The optical characteristics of four kinds of aminoacids (tyrosine, arginine, histidine and glutamine) filled with nitrogen at room temperature were studied by THz time-domain spectroscopy (THz-TDS). Well-resolved absorption and refractive spectrums between 0.1 and 2.8 THz were obtained based on the physical model for extracting the optical parameters of materials in THz range. The results not only fill up the spectra gap of aminoacids in far-infrared range, supply data for aminoacid molecular identification and conformation analysis, but also demonstrate significantly potential to promote the research and application of biological materials in bio-chemical and medical fields by THz-TDS.

A mechanism for creating aminoacid enantiomerism that always selects the same global chirality is identified, and subsequent chemical replication and galactic mixing that would populate the galaxy with the predominant species is described. This involves: (1) the spin of the 14N in the aminoacids, or in precursor molecules from which aminoacids might be formed, coupling to the chirality of the molecules; 2) the neutrinos emitted from the supernova, together with magnetic field from the nascent neutron star or black hole formed from the supernova selectively destroying one orientation of the 14N, and thus selecting the chirality associated with the other 14N orientation; (3) chemical evolution, by which the molecules replicate and evolve to more complex forms of a single chirality on a relatively short timescale; and (4) galactic mixing on a longer timescale mixing the selected molecules throughout the galaxy.

An association between sulfur aminoacids (methionine, cysteine, homocysteine and taurine) and lipid metabolism has been described in several experimental and population-based studies. Changes in the metabolism of these aminoacids influence serum lipoprotein concentrations, although the underlying mechanisms are still poorly understood. However, recent evidence has suggested that the enzyme stearoyl-CoA desaturase-1 (SCD-1) may be the link between these two metabolic pathways. SCD-1 is a key enzyme for the synthesis of monounsaturated fatty acids. Its main substrates C16:0 and C18:0 and products palmitoleic acid (C16:1) and oleic acid (C18:1) are the most abundant fatty acids in triglycerides, cholesterol esters and membrane phospholipids. A significant suppression of SCD-1 has been observed in several animal models with disrupted sulfur aminoacid metabolism, and the activity of SCD-1 is also associated with the levels of these aminoacids in humans. This enzyme also appears to be involved in the etiology of metabolic syndromes because its suppression results in decreased fat deposits (regardless of food intake), improved insulin sensitivity and higher basal energy expenditure. Interestingly, this anti-obesogenic phenotype has also been described in humans and animals with sulfur aminoacid disorders, which is consistent with the hypothesis that SCD-1 activity is influenced by these aminoacids, in particularly cysteine, which is a strong and independent predictor of SCD-1 activity and fat storage. In this narrative review, we discuss the evidence linking sulfur aminoacids, SCD-1 and lipid metabolism.

The analysis of carbohydrates and aminoacids in green coffee is of the utmost importance since these two classes of compounds act as precursors of the Maillard reaction during which the colour and aroma are formed. During the course of the Maillard reaction potentially harmful substances like acrylamide or 5-hydroxymethyl-furfural accrue as well. The carbohydrates were analysed by anion-exchange chromatography with pulsed amperometric detection and the aminoacids by reversed phase chromatography after derivatization with 6-amino-quinolyl-N-hydroxysuccinimidyl carbamate and fluorescence detection. Both methods had to be optimized to obtain a sufficient resolution of the analytes for identification and quantification. Sucrose is the dominant carbohydrate in green coffee with a concentration of up to 90 mg/g (mean = 73 mg/g) in arabica beans and significantly lower amounts in robusta beans (mean=45 mg/g). Alanine is the aminoacid with the highest concentration (mean = 1200 microg/g) followed by asparagine (mean = 680 microg/g) in robusta and 800 microg/g and 360 microg/g in arabica respectively. In general, the concentration of aminoacids is higher in robusta than in arabica.

Full Text Available Application of a factorial method for determining the needs in metabolic protein and essential aminoacids, helps to deepen knowledge on physiology of protein and aminoacid supply and allow to improve the standards for dairy cows during the transition period; in insufficient of metabolic protein and essential aminoacids increased coefficients of their transformation into net protein and absorptive aminoacids as a result of mobilization of body of cows; with an optimal protein nutrition their transformation in net milk protein, lysine and methionine accordingly amounted to 0.67, 0,83 and 0,82. The most significant changes in the concentration of methionine, proline, glutamate, glutamine, glycine were observed in cows before calving and immediately after birth, stabilization of their level starts with a 24 lactation day, that is connected with the peculiarities of the feeding behavior of the cows and the gradual intensification of the processes of metabolism and milk production. To control the status of protein metabolism we have offered benchmarks compositions of free aminoacids in cows’ blood plasma phases: 21-0 days before calving, 0-21 and 22-120 days after calving

The aliphatic aminoacids L-alanine and L-leucine and the aromatic aminoacids L-phenylalanine, L-tyrosine and L-tryptophan were irradiated in the solid state to a dose of 3.2 MGy. The degree of decomposition was measured by differential scanning calorimetry (DSC). Furthermore the degree of radioracemization was measured by optical rotatory dispersion (ORD) spectroscopy. From the DSC measurement a radiolysis rate constant k and the half life T1/2 for each aminoacid have been determined and extrapolated to a dose of 14 MGy, which corresponds to the expected total dose delivered by the decay of radionuclides to the organic molecules present in comets and asteroids in 4.6×109 years, the age of the Solar System. It is shown that all the aminoacids studied can survive a radiation dose of 14 MGy although they are reduced to 1/4-1/5 of their original value they had at the beginning of the history of the Solar System. Consequently, the amount of alanine or leucine found today in the meteorites known as carbonaceous chondrites is just 1/4-1/5 of the amount originally present at the epoch of the formation of the Solar System 4.6×109 years ago. Among the aminoacids studied, tyrosine shows the highest radiation resistance while tryptophan does not combine its relatively high radiation resistance with an elevated level of radioracemization resistance. Apart from the exception of tryptophan, it is shown that the radiolysis rate constants k of all the aminoacids studied are in reasonable agreement with the radioracemization rate constant krac.

The aliphatic aminoacids L-alanine and L-leucine and the aromatic aminoacids L-phenylalanine, L-tyrosine and L-tryptophan were irradiated in the solid state to a dose of 3.2 MGy. The degree of decomposition was measured by differential scanning calorimetry (DSC). Furthermore the degree of radioracemization was measured by optical rotatory dispersion (ORD) spectroscopy. From the DSC measurement a radiolysis rate constant k and the half life T{sub 1/2} for each aminoacid have been determined and extrapolated to a dose of 14 MGy, which corresponds to the expected total dose delivered by the decay of radionuclides to the organic molecules present in comets and asteroids in 4.6x10{sup 9} years, the age of the Solar System. It is shown that all the aminoacids studied can survive a radiation dose of 14 MGy although they are reduced to 1/4-1/5 of their original value they had at the beginning of the history of the Solar System. Consequently, the amount of alanine or leucine found today in the meteorites known as carbonaceous chondrites is just 1/4-1/5 of the amount originally present at the epoch of the formation of the Solar System 4.6x10{sup 9} years ago. Among the aminoacids studied, tyrosine shows the highest radiation resistance while tryptophan does not combine its relatively high radiation resistance with an elevated level of radioracemization resistance. Apart from the exception of tryptophan, it is shown that the radiolysis rate constants k of all the aminoacids studied are in reasonable agreement with the radioracemization rate constant k{sub rac}.

The problems such as chromogenic reaction selectivity, reaction rate, sensitivity and water-solubility of azo compounds were considered. The molecular structures of coupling components were theoretically designed and screened in the present research The reaction conditions and methods of chromogenic reaction were investigated. J-Acid (2-amino-5-naphthol-7-sulfonic acid) as a coupling reagent to determine aromatic amino compounds was established. In the presence of potassium bromide, at room temperature, nitrite reacted with aromatic amino compounds in the medium of thin hydrochloric acid. Then diazonium salt reacted with J-Acid in the aqueous solution of sodium carbonate, forming coloured azo dye, which had a maximum adsorption at 480 nm. The molar adsorption coeffcients of aniline, 4-aminobenzene sulfonic acid and 1-naphthylamine were 3. 95 X 10(4), 3. 24 X 10(4) and 3. 91 X 10(4) L . mol-1 . cm-1 , respectively. Experimental results showed that common coexisting ions on the surface water did not affect the results of determination. J-Acid of spectrophotometry was used to determine the samples of Shanghai Fu Xing Dao canal. Meanwhile, recovery experiments by standard addition method were done. Experiment results showed that the recoveries of aniline were in the range of 98. 5%-102. 1%, and RSD was 2. 08%. J-Acid is a common organic reagent. It is soluble in water and low volatile, and its toxicity is much lower than N-ethylenediamine. spectrophotometric determination of aromatic amino compounds by J-Acid has the advantage of high sensitivity, good selectivity, simple rapid operation and accurate results, and thus it can be used for the determination of trace aromatic amino compounds in the environmental water.

Charges are considered an integral part of protein structure and function, enhancing solubility and providing specificity in molecular interactions. We wished to investigate whether charged aminoacids are indeed required for protein biogenesis and whether a protein completely free of titratable...... side chains can maintain solubility, stability, and function. As a model, we used a cellulose-binding domain from Cellulomonas fimi, which, among proteins of more than 100 aminoacids, presently is the least charged in the Protein Data Bank, with a total of only four titratable residues. We find...

The interaction between pathogenic microorganisms and their hosts is regulated by reciprocal survival strategies, including competition for essential nutrients. Though paradoxical, mammalian hosts have learned to take advantage of aminoacid catabolism for controlling pathogen invasion and, at the same time, regulating their own immune responses. In this way, ancient catabolic enzymes have acquired novel functions and evolved into new structures with highly specialized functions, which go beyond the struggle for survival. In this review, we analyze the evidence supporting a critical role for the metabolism of various aminoacids in regulating different steps of both innate and adaptive immunity.

Serine deficiency disorders are rare defects in the biosynthesis of the aminoacid L-serine. At present two disorders have been reported: 3-phosphoglycerate dehydrogenase deficiency and 3-phosphoserine phosphatase deficiency. These enzyme defects lead to severe neurological symptoms such as congenital microcephaly and severe psychomotor retardation and in addition in patients with 3-phosphoglycerate dehydrogenase deficiency to intractable seizures. These symptoms respond to a variable degree to treatment with L-serine, sometimes combined with glycine. In this paper the current practice of aminoacid treatment with L-serine and glycine in serine deficiency is reviewed.

Diabetic retinopathy is a leading cause of vision loss. The primary clinical hallmarks are vascular changes that appear to contribute to the loss of sight. In a number of neurodegenerative disorders there is an appreciation that increased levels of excitatory aminoacids are excitotoxic. The primary aminoacid responsible appears to be the neurotransmitter glutamate. This review examines the nature of glutamatergic signaling at the retina and the growing evidence from clinical and animal model studies that glutamate may be playing similar excitotoxic roles at the diabetic retina. PMID:17713594

Full Text Available Diabetic retinopathy is a leading cause of vision loss. The primary clinical hallmarks are vascular changes that appear to contribute to the loss of sight. In a number of neurodegenerative disorders there is an appreciation that increased levels of excitatory aminoacids are excitotoxic. The primary aminoacid responsible appears to be the neurotransmitter glutamate. This review examines the nature of glutamatergic signaling at the retina and the growing evidence from clinical and animal model studies that glutamate may be playing similar excitotoxic roles at the diabetic retina.

Aminoacids, especially glutamine (GLN) have been known for many years to stimulate the growth of small intestinal mucosa. Polyamines are also required for optimal mucosal growth, and the inhibition of ornithine decarboxylase (ODC), the first rate-limiting enzyme in polyamine synthesis, blocks growth. Certain aminoacids, primarily asparagine (ASN) and GLN stimulate ODC activity in a solution of physiological salts. More importantly, their presence is also required before growth factors and hormones such as epidermal growth factor and insulin are able to increase ODC activity. ODC activity is inhibited by antizyme-1 (AZ) whose synthesis is stimulated by polyamines, thus, providing a negative feedback regulation of the enzyme. In the absence of aminoacids mammalian target of rapamycin complex 1 (mTORC1) is inhibited, whereas, mTORC2 is stimulated leading to the inhibition of global protein synthesis but increasing the synthesis of AZ via a cap-independent mechanism. These data, therefore, explain why ASN or GLN is essential for the activation of ODC. Interestingly, in a number of papers, AZ has been shown to inhibit cell proliferation, stimulate apoptosis, or increase autophagy. Each of these activities results in decreased cellular growth. AZ binds to and accelerates the degradation of ODC and other proteins shown to regulate proliferation and cell death, such as Aurora-A, Cyclin D1, and Smad1. The correlation between the stimulation of ODC activity and the absence of AZ as influenced by aminoacids is high. Not only do aminoacids such as ASN and GLN stimulate ODC while inhibiting AZ synthesis, but also aminoacids such as lysine, valine, and ornithine, which inhibit ODC activity, increase the synthesis of AZ. The question remaining to be answered is whether AZ inhibits growth directly or whether it acts by decreasing the availability of polyamines to the dividing cells. In either case, evidence strongly suggests that the regulation of AZ synthesis is the

Surveys the roots of the common names of organic compounds most likely to be encountered by undergraduate organic chemistry students. Includes information for 19 aminoacids, 17 aromatic compounds, and 21 carboxylic acids. (WRM)

The absorption of lysine is facilitated by leucine, but there is no information regarding the effect of crude protein, lysine and leucine levels on the expression of cationic aminoacid transporters in pigs. Therefore, an experiment was conducted with 20 pigs (14.9 +/- 0.62 kg initial body weight) to evaluate the effect of two protein levels, and the content of lysine, threonine, methionine and leucine in low crude protein diets on the expression of b(0,+) and CAT-1 mRNA in jejunum, Longissimus dorsi and Semitendinosus muscles and serum concentration of aminoacids. Treatments were as follows: (i) wheat-soybean meal diet, 20% crude protein (Control); (ii) wheat diet deficient in lysine, threonine and methionine (Basal diet); (iii) Basal diet plus 0.70% L-lysine, 0.27% L-threonine, 0.10% DL-methionine (Diet LTM); (iv) Diet LTM plus 0.80% L-leucine (Diet LTM + Leu). Despite the Basal diet, all diets were formulated to meet the requirements of lysine, threonine and methionine; Diet LTM + Leu supplied 60% excess of leucine. The addition of lysine, threonine and methionine in Diet LTM increased the expression of b(0,+) in jejunum and CAT-1 in the Semitendinosus and Longissiums muscles and decreased CAT-1 in jejunum; the serum concentration of lysine was also increased (p Pigs fed the Control diet expressed less b(0,+) in jejunum, and CAT-1 in the Semitendinosus and Longissiums muscles expressed more CAT-1 in jejunum (p dietary aminoacids, affect the expression of cationic aminoacid transporters in pigs fed wheat-based diets.

An efficient method for the preparation of chromone based α-aminoacid derivatives by alkylation of glycinate schiff base with 3-bromomethyl chromone as well as 2-bromomethyl chromone has been described. Using this method, 2-amino-3-(4-oxo-2-chromenyl)propanoic acid and 2-amino-3-(4-oxo-3- chromenyl)propanoic acid, two novel chromone-aminoacid conjugates have been prepared. Furthermore, the separation of chromone aminoacid enantiomers by chiral column chromatography was accomplished.

In 36 growing pigs (30 to 60 kg), N balance and aminoacid (AA) composition of weight gain were measured to evaluate the interactive effect of the ratio between N from essential aminoacids (EAA(N)) to nonessential aminoacids (NEAA(N)) and total N level (T(N)) in the diet on N retention and

Complete diallel crosses with five parents of common wheat (Triticum aestivum L.) were conducted to analyse inheritance of 17 aminoacid contents by using the genetic model including seed, cytoplasmic, maternal and environment interaction effects on quantitative traits of seeds in cereal crops. The results showed that inheritance of 17 aminoacid contents, except tyrosine, was controlled by several genetic systems including seed, cytoplasmic, and maternal effects, and by significant gene × environment interaction effects. Seed-direct additive and maternal effects constituted a major part of genetic effects for lysine, tyrosine, arginine, methionine, and glutamic acid content. Seed-direct additive effect formed main part in inheritance of isoleucine and serine contents. Threonine content was mainly governed by maternal additive effect. The other nine aminoacid contents were almost entirely controlled by dominance effects. High general heritability of tyrosine (36.3%), arginine (45.8%), lysine (24.7%) and threonine (21.4%) contents, revealed that it could be effective to improve them by direct selection in progenies from appropriate crosses. Interaction heritability for phenylalanine, proline, and histidine content, which was 36.1%, 39.5% and 25.7%, respectively, was higher than for the other aminoacids.

The fate of microbial carbon, nitrogen, hydrolysable aminoacids (HAAs), monosaccharides, and fatty acids in sediment was investigated experimentally. The microbial community of a tidal flat sediment was labeled with C-13-enriched glucose and N-15-enriched ammonium, and sediment was incubated for up to 371 days. Analysis of total concentrations and C-13- and N-15 content of bulk sediment, hydrolysable aminoacids (including D-alanine), monosaccharides, total fatty acids (TFAs), and phospholip...

Full Text Available In the title compound, C12H15NO4, the butyric acid group has a stretched trans conformation. The dihedral angle between the phenyl ring and the oxycarboxyamino N—(C=O—O—C plane is 56.6 (2°. In the crystal, an inversion dimer is formed by a pair of O—H...O hydrogen bonds. The dimers are further linked by N—H...O hydrogen bonds between amide groups, forming a tape along the b axis.

Full Text Available BACKGROUND: Microsatellites have been used extensively in the field of comparative genomics. By studying microsatellites in coding regions we have a simple model of how genotypic changes undergo selection as they are directly expressed in the phenotype as altered proteins. The simplest of these tandem repeats in coding regions are the tri-nucleotide repeats which produce a repeat of a single aminoacid when translated into proteins. Tri-nucleotide repeats are often disease associated, and are also known to be unstable to both expansion and contraction. This makes them sensitive markers for studying proteome evolution, in closely related species. RESULTS: The evolutionary history of the family of malarial causing parasites Plasmodia is complex because of the life-cycle of the organism, where it interacts with a number of different hosts and goes through a series of tissue specific stages. This study shows that the divergence between the primate and rodent malarial parasites has resulted in a lineage specific change in the simple aminoacid repeat distribution that is correlated to A-T content. The paper also shows that this altered use of aminoacids in SAARs is consistent with the repeat distributions being under selective pressure. CONCLUSIONS: The study shows that simple aminoacid repeat distributions can be used to group related species and to examine their phylogenetic relationships. This study also shows that an outgroup species with a similar A-T content can be distinguished based only on the aminoacid usage in repeats, and suggest that this might be a useful feature for proteome clustering. The lineage specific use of aminoacids in repeat regions suggests that comparative studies of SAAR distributions between proteomes gives an insight into the mechanisms of expansion and the selective pressures acting on the organism.

Aminoacid analysis is a highly accurate method for characterization of the composition of synthetic peptides. Together with mass spectrometry, it gives a reliable control of peptide quality and quantity before conjugation and immunization.Peptides are hydrolyzed, preferably in gas phase, with 6 M...... HCl at 110 °C for 20-24 h and the resulting aminoacids analyzed by ion-exchange chromatography with post-column ninhydrin derivatization. Depending on the hydrolysis conditions, tryptophan is destroyed, and cysteine also, unless derivatized, and the amides, glutamine and asparagine, are deamidated...... to glutamic acid and aspartic acid, respectively. Three different ways of calculating results are suggested, and taking the above limitations into account, a quantitation better than 5 % can usually be obtained....

Autism is a complex and life-long behavioural disorder of unknown aetiology. Recent reports have indicated the involvement of digestive tract dysfunction and possible complications from inadequate nutrition. In this study, 34 autistic children (12 untreated and 22 receiving therapeutic treatments related to digestive function and nutritional uptake) and 29 control subjects (all 5-15 years of age) were investigated to determine whether there were any anomalies in the urinary excretion of aminoacids, glucose, sucrose, arabinose and tartaric acid using GC/FID and GC/MS analysis techniques. Significantly lower relative urinary levels of essential aminoacids were revealed for both the untreated (mean +/- SEM, 32.53 +/- 3.09%) and treated (31.98 +/- 2.87%) autistic children compared with the controls (37.87 +/- 1.50%). There were no significant differences in measured excretions of sugars or tartaric acid. It was concluded that the untreated autistic children had evidence of altered metabolic homeostasis.

Full Text Available Chiral behavior of magnetoelectrodeposited (MED Cu film electrodes was investigated for the electrochemical reactions of aminoacids. The Cu films were electrodeposited under a magnetic field of 5 T perpendicular to the electrode surface. Such MED Cu films were employed as an electrode, and cyclic voltammograms were measured for the electrochemical reactions of several kinds of aminoacids. Chiral behavior was clearly observed as oxidation current difference between the enantiomers of alanine, aspartic acid, and glutamic acid. The MED film electrodes with the thickness of 50~500 nm exhibited such chiral behavior, and their surface morphologies had network structures, which could be induced by the micro-MHD effect.

Glutamic acid is an important excitatory neurotransmitter of the brain. Two key goals of brain aminoacid handling are to maintain a very low intrasynaptic concentration of glutamic acid and also to provide the system with precursors from which to synthesize glutamate. The intrasynaptic glutamate level must be kept low to maximize the signal-to-noise ratio upon the release of glutamate from nerve terminals and to minimize the risk of excitotoxicity consequent to excessive glutamatergic stimulation of susceptible neurons. The brain must also provide neurons with a constant supply of glutamate, which both neurons and glia robustly oxidize. The branched-chain aminoacids (BCAAs), particularly leucine, play an important role in this regard. Leucine enters the brain from the blood more rapidly than any other aminoacid. Astrocytes, which are in close approximation to brain capillaries, probably are the initial site of metabolism of leucine. A mitochondrial branched-chain aminotransferase is very active in these cells. Indeed, from 30 to 50% of all alpha-amino groups of brain glutamate and glutamine are derived from leucine alone. Astrocytes release the cognate ketoacid [alpha-ketoisocaproate (KIC)] to neurons, which have a cytosolic branched-chain aminotransferase that reaminates the KIC to leucine, in the process consuming glutamate and providing a mechanism for the "buffering" of glutamate if concentrations become excessive. In maple syrup urine disease, or a congenital deficiency of branched-chain ketoacid dehydrogenase, the brain concentration of KIC and other branched-chain ketoacids can increase 10- to 20-fold. This leads to a depletion of glutamate and a consequent reduction in the concentration of brain glutamine, aspartate, alanine, and other aminoacids. The result is a compromise of energy metabolism because of a failure of the malate-aspartate shuttle and a diminished rate of protein synthesis.

Prosthecae purified from cells of Asticcaulis biprosthecum possess active transport systems that transport all 20 aminoacids tested. Using ascorbate-reduced phenazine methosulphate in the presence of oxygen, all 20 aminoacids are accumulated against a concentration gradient by isolated prosthecae. Results of experiments testing the inhibition of transport of one aminoacid by another, and of experiments testing the exchange of exogenous aminoacids with those preloaded in prosthecae, along with characteristics of mutants defective in aminoacid transport, suggest the presence in prosthecae of three aminoacid transport systems. One, the general or G system, transports at least 18 of the 20 aminoacids tested. Another system, referred to as the proline or P system, transports seven aminoacids (including proline) that are also transported by the G system. The third system transports only glutamate and aspartate, and is referred to as the acidicaminoacid transport system or A system.

Full Text Available Aminoacids are important sources of soil organic nitrogen (N, which is essential for plant nutrition, but detailed information about which aminoacids predominant and whether aminoacid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of aminoacids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of aminoacids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and aminoacids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N. On average, soil adsorbed aminoacid concentration was approximately 5-fold greater than that of the free aminoacids, which indicates that adsorbed aminoacids extracted with the strong salt solution likely represent a potential source for the replenishment of free aminoacids. We found no appreciable evidence to suggest that aminoacids with simple molecular structure were dominant at low elevations, whereas aminoacids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the aminoacid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven aminoacids accounted for approximately 68.9% of the total hydrolyzable aminoacid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major aminoacid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine did not vary appreciably with elevation (p>0.10. The compositional

Levels of free D-aminoacids were compared in 11 vinegars produced from different sources or through different manufacturing processes. To analyze the D- and L-aminoacids, the enantiomers were initially converted into diastereomers using pre-column derivatization with o-phthaldialdehyde plus N-acethyl-L-cysteine or N-tert-butyloxycarbonyl-L-cysteine. This was followed by separation of the resultant fluorescent isoindol derivatives on an octadecylsilyl stationary phase using ultra-performance liquid chromatography. The analyses showed that the total D-aminoacid level in lactic fermented tomato vinegar was very high. Furthermore, analysis of the aminoacids in tomato juice samples collected after alcoholic, lactic and acetic fermentation during the production of lactic fermented tomato vinegar showed clearly that lactic fermentation is responsible for the D-aminoacids production; marked increases in D-aminoacids were seen during lactic fermentation, but not during alcoholic or acetic fermentation. This suggests lactic acid bacteria have a greater ability to produce D-aminoacids than yeast or acetic acid bacteria.

Chlorine dioxide is a hypochlorite alternative disinfectant agent. In this context, we have determined the products formed in the reaction of ClO{sub 2} with selected aminoacids as model compounds that can be present in natural waters. The reaction of tryptophane, histidine and tyrosine (10 ppm each) with ClO{sub 2} were studied at molar ratios ranging from 0.25 to 4 in the presence or absence of oxygen. It was found that in the absence of oxygen adding substoichiometric amounts of ClO{sub 2} creates products that are structurally similar to the starting aminoacids. Through a series of cascade reactions the initial product distribution gradually evolves toward simple, small carbon chain products that are far from the starting aminoacid. The reaction product distribution revealed that chlorine dioxide can attack the electron-rich aromatic moieties as well as the nitrogen atom lone electron pair. Our study is relevant to gain knowledge on the reaction mechanism of ClO{sub 2} with ubiquitous aminoacids present in natural waters.

This paper reports the responses of taste cells on the legs of the blood-feeding tsetse fly Glossina fuscipes fuscipes Newstead 1910 (Diptera: Glossinidae) to twenty protein aminoacids and to their mixture as it is present in human;sweat. It is investigated whether the mixture is sensed differently

The use of arctigenin (ARG), a traditional medicine with many pharmacological activities, has been restricted due to its poor solubility in water. Five aminoacid derivatives of ARG have been synthesized using glycine, o-alanine, valine, leucine, and isoleucine, which have t-butyloxy carbonyl (BOC) as a protective group. In this study, we examined the effects of removing these protective groups. The results showed that the aminoacid derivatives have better solubility and nitrite-clearing ability than ARG. Among the compounds tested, the aminoacid derivatives without protective group were the best. Based on these results, ARG and its two aminoacid derivatives without protective group (ARG8, ARG10) were selected to evaluate their anti-tumor activity in vivo at a dosage of 40 mg/kg. The results indicated that ARG8 and ARG10 both exhibit more anti-tumor activity than ARG in H22 tumor-bearing mice. The tumor inhibition rates of ARG8 and ARG10 were 69.27 and 43.58%, which was much higher than ARG. Furthermore, the mice treated with these compounds exhibited less damage to the liver, kidney and immune organs compared with the positive group. Furthermore, ARG8 and ARG10 improved the serum cytokine levels significantly compared to ARG. In brief, this study provides a method to improve the water solubility of drugs, and we also provide a reference basis for new drug development.

The development of a new astrobiolgoy instrument for exploring the trace chemical composition of the Enceladus jets and plume, and the e-ring of Saturn is presented. The Enceladus aminoacid sampler (EAAS) allows for detection of aminoacids using optical Raman spectroscopy integrated with a sample pre-concentration system. The pre-concentration process facilitates the delivery of a sample to a mass spectrometer for detection of specific aminoacids. The initial EAAS design utilizes lab-on-a-breadboard components where a sample inlet, sample outlet, reagents, controllers, pumps, valves and pre-concentration column for the EAAS prototype are all assembled on a 5" x 7" breadboard. The pre-concentration process is controlled using automation scripts and software. An optical window allows a Raman spectrometer to directly monitor the pre-concentration of aminoacids in a filter/column loaded with of a strong cation exchange resin. Initial samples to demonstrate EAAS simulate the conditions of Don Juan Pond, one of the coldest and saltiest bodies of liquid water on Earth, located in the Wright Valley of Antarctica. This EAAS development is an important step toward a new type of astrobiology science instrument that is capable of operating on a spacecraft in flight or in orbit.

This thesis describes the functional characterisation of the transcriptional regulators GlnR, ArgR and AhrC of Lactococcus lactis, which are responsible for the control of genes involved in the metabolism of the aminoacids glutamine, glutamate and arginine. A chromosomal glnR deletion mutant was ma

This work summarises the results of the design of novel separation processes for CO2 removal from flue gas based on precipitating aminoacid solvents. The processes here described (DECAB, DECAB Plus and pH-swing) use a combination of enhanced CO2 absorption (based on the Le Chatelier’s principle) an

-chain aminoacids (BCAA) versus control interventions has evaluated if BCAA may benefit people with hepatic encephalopathy. OBJECTIVES: To evaluate the beneficial and harmful effects of BCAA versus any control intervention for people with hepatic encephalopathy. SEARCH METHODS: We identified trials through...

Full Text Available Abstract Background Finding the aminoacid mutations that affect the severity of influenza infections remains an open and challenging problem. Of special interest is better understanding how current circulating influenza strains could evolve into a new pandemic strain. Influenza proteomes from distinct viral phenotype classes were searched for class specific aminoacid mutations conserved in past pandemics, using reverse engineered linear classifiers. Results Thirty-four aminoacid markers associated with host specificity and high mortality rate were found. Some markers had little impact on distinguishing the functional classes by themselves, however in combination with other mutations they improved class prediction. Pairwise combinations of influenza genomes were checked for reassortment and mutation events needed to acquire the pandemic conserved markers. Evolutionary pathways involving H1N1 human and swine strains mixed with avian strains show the potential to acquire the pandemic markers with a double reassortment and one or two aminoacid mutations. Conclusion The small mutation combinations found at multiple protein positions associated with viral phenotype indicate that surveillance tools could monitor genetic variation beyond single point mutations to track influenza strains. Finding that certain strain combinations have the potential to acquire pandemic conserved markers through a limited number of reassortment and mutation events illustrates the potential for reassortment and mutation events to lead to new circulating influenza strains.

predicted from digestibility values, suggests that aminoacids might be limiting for milk production in the case of certain feedstuff s. S. Afr. J. Anim. ... nutritional parameter of recognized value (Scott, Nesheim. & Young, 1976). ... It would be a function simply of (i) the ...... value of human and cow's milk colostrum. World Rev.

Full Text Available Aminoacids are involved in many scientific theories elucidating possible origins of life on Earth. One of the challenges when discussing the evolutionary origin of biopolymers such as proteins and oligonucleotides in living organisms is the phenomenon that these polymers implement monomers of exclusively one handedness, a feature called biomolecular homochirality. Many attempts have been made to understand this process of racemic symmetry breaking. Assuming an extraterrestrial origin of the molecular building blocks of living organisms, their susceptibility to asymmetric photolysis by the absorption of circularly polarized electromagnetic radiation in interstellar space was proposed. In order to predict whether the interaction of circularly polarized light with various racemic aminoacids can induce an enantiomeric excess, we investigated the electronic and chiroptical properties of the aminoacids valine and isovaline by a molecular modelling approach based on quantum chemistry (Density Functional Theory. The average spectra of both L-valine and L-isovaline have been produced on the basis of Boltzmann population analysis using computed spectra for the various conformations of each aminoacid.

Waste water usually contains large amounts of different organic compounds. A variety of microbial processes are involved in the anaerobic methanogenic treatment of waste water, such as hydrolysis of lipids, polysaccharides and proteins, fermentation of sugars and aminoacids, acetogenic conversion o

Reactive absorption is a common process in the chemical industry and is used, among others, in the treatment of CO2 containing industrial gas streams. The current work was a part of a project with the aim to assess new reactive solvents based on aminoacid salts for CO2 removal from industrial gas s

-chain aminoacids (BCAA) versus control interventions has evaluated if BCAA may benefit people with hepatic encephalopathy. OBJECTIVES: To evaluate the beneficial and harmful effects of BCAA versus any control intervention for people with hepatic encephalopathy. SEARCH METHODS: We identified trials through...

Sufu is a Chinese soybean cheese-like product obtained by solid-state fungal fermentation and ripening of tofu. The resulting "pehtze" is salted, followed by maturation in brine. Total (TAA) and free aminoacid (FAA) profiles were determined during consecutive stages of sufu manufacture, i.e., tofu,

Integration of a micro-chip capillary electrophoresis analyzer with a sublimation-based extraction technique, as used in the Mars Organic Detector (MOD), for the in-situ detection of aminoacids and their enantiomers on solar system bodies. Additional information is contained in the original extended abstract.

Glycosylamines contain the easily cleavable semi-aminal-type N-glycosidic bond. O-Protected glycosylamines, therefore, can advantageously be used as a form of "asymmetric ammonia", for instance, in Strecker syntheses and in Ugi reactions to give aminoacid amides as well as in modifications of the Mannich reaction.

Two coamorphous drug−aminoacid systems, indomethacin−tryptophan (Ind−Trp) and furosemide−tryptophan Fur−Trp), were analyzed toward their ease of amorphization and mechanism of coamorphization during ball milling. The two mixtures were compared to the corresponding amorphization of the pure drug...

Aminoacidopathies are a group of rare and diverse disorders, caused by the deficiency of an enzyme or transporter involved in aminoacid metabolism. For most aminoacidopathies, dietary management is the mainstay of treatment. Such treatment includes severe natural protein restriction, combined with

@@ Phosphoramidates have been considered as an important class of rationally designed therapeutics especially asoligonucleotide analogs employed as antisene and antigene agents. [1] N-Phosphoryl aminoacids are of biological andpharmaceutical interest, [2] and can be used as the building blocks in synthesis of polypeptides. [3

Full Text Available The antibacterial properties of differently copper and cobalt aminoacids complexes on agar plates was investigated in the present study. The antibacterial activity of aminoacid complexes was evaluated against on three bacteria strains (Escherichia coli, Bacillus cereus, Micrococcus luteus. Generally, the aminoacids complexes were mainly active against gram-positive organisms, species like Micrococcus luteus being the most susceptible strain tested. It was registered a moderate antibacterial activity against Bacillus cereus. The microorganisms Escherichia coli, which are already known to be multi-resistant to drugs, were also resistant to the aminoacids complexes but also to the free salts tested. Escherichia coli were susceptible only to the CoCl2 and copper complex with phenylalanine. The complexes with leucine and histidine seem to be more active than the parent free ligand against one or more bacterial species. Moderate activity was registered in the case of complexes with methionine and phenylalanine. From the complexes tested less efficient antibacterial activity was noted in the case of complexes with lysine and valine. These results show that cobalt and copper complexes have an antibacterial activity and suggest their potential application as antibacterial agents.

The theoretical prediction of H atom elimination on the excited state of phenol, imidazole and indole, the respective chromophores for the aminoacids tyrosine, histidine and tryptophan, and the confirmation of theoretical prediction by experimental observations have a great impact on the explanation of photostability of aminoacids upon irradiation with UV photons. On the other hand, no theoretical prediction of the excited state photodissociation dynamics has been made on the other aromatic aminoacid, phenylalanine. In this work, photodissociation dynamics for various phenylalanine chromophores, including, phenylethylamine, N-methyl-phenylethylamine, and N-acetyl phenylalanine methyl ester was investigated in a molecular beam at 248 and 193 nm using multimass ion imaging techniques. The major dissociation channel for these compounds is the C-C bond cleavage. However, the photofragment translational energy distribution of phenylethylamine contains two components. The slow component corresponds to the dissociation on the ground state surface after internal conversion, and the fast component represents the dissociation from an excited state with a large exit barrier. The competition between the dissociation on the ground state and on the excited state changes as the size of chromophores increases. Internal conversion to the ground state prior to dissociation becomes the major nonradiative process for large chromophores. This study reveals the size-dependent photostability for these aminoacid chromophores.

Charges are considered an integral part of protein structure and function, enhancing solubility and providing specificity in molecular interactions. We wished to investigate whether charged aminoacids are indeed required for protein biogenesis and whether a protein completely free of titratable ...

Gas-phase infrared multiple photon dissociation (IRMPD) spectra have been recorded for the conjugate bases of a series of aminoacids (Asp, Cys, Glu, Phe, Set, Trp, Tyr). The spectra are dominated by strong symmetric and antisymmetric carboxylate stretching modes around 1300 and 1600 cm(-1),

The main objective of the present study was to identify simple sequence repeat (SSR) markers associated with the aminoacid content of rice (Oryza sativa L.). SSR markers were selected by prescreening for the relationship to aminoacid content. Eighty-four rice landrace accessions from Korea were evaluated for 16 kinds of aminoacids in brown rice and genotyped with 25 SSR markers. Analysis of population structure revealed four subgroups in the population. Linkage disequilibrium (LD) patterns and distributions are of fundamental importance for genome-wide mapping associations. The mean r2 value for all intrachromosomal loci pairs was 0.033. LD between linked markers decreased with distance. Marker-trait associations were investigated using the unified mixed-model approach, considering both population structure (Q) and kinship (K). A total of 42 marker-trait associations with aminoacids (P < 0.05) were identified using 15 different SSR markers covering three chromosomes and explaining more than 40% of the total variation. These results suggest that association analysis In rice is a viable alternative to quantitative trait loci mapping and should help rice breeders develop strategies for improving rice quality.

Aminoacidopathies are a group of rare and diverse disorders, caused by the deficiency of an enzyme or transporter involved in aminoacid metabolism. For most aminoacidopathies, dietary management is the mainstay of treatment. Such treatment includes severe natural protein restriction, combined with

Exposure of aminoacids, peptides and proteins to radicals in the presence of O2 generates hydroperoxides in a dose-dependent manner. These hydroperoxides are stable in the absence of exogenous catalysts (e.g. heat, light, redox-active transition metal ions), but decompose rapidly in the presence...

Stunting affects about one-quarter of children under five worldwide. The pathogenesis of stunting is poorly understood. Nutritional interventions have had only modest effects in reducing stunting. We hypothesized that insufficiency in essential aminoacids may be limiting the linear growth of childr...

Full Text Available Investigators from Hospital Sant Joan de Deu, Barcelona, Spain, studied the relationship between the etiology of refractory childhood epilepsy, CSF neurotransmitters, pterins, and aminoacids, and response to a ketogenic diet in 60 patients with refractory epilepsy, 83% focal and 52% idiopathic.

Aminoacids are involved in many important physiological processes affecting the production, health, and reproduction of high-producing dairy cows. Most research and recommendations for lactating dairy cows has focused on methionine and lysine for increasing milk protein yield. This is because these...

Full Text Available Phenylalanine (Phe and tyrosine (Tyr are two of the twenty aminoacids in proteins; they are classified as aromatic aminoacids, because both have a benzene ring in their structures. These aminoacids are important in the synthesis of several biologically active amines, such as beta-endorphin, a neurotransmitter. Aminoacids can be separated by ion-exchange chromatography. In this case, it is important that fixed-bed adsorber design adequately predict the breakthrough curve. This work presents a mathematical model for both fluid and porous phases. In the solution proposed for this model the liquid-phase concentration inside the particles is solved analytically and is related to the liquid-phase concentration in the bed using Duhamel's theorem. The solution for liquid-phase concentration in the bed is then solved numerically instead of analytically. The basic mass transfer parameters are from the literature. The results from the model are compared with those obtained experimentally using Phe and Tyr diluted in aqueous solutions in a fixed bed of PVP (poly-4-vinylpyridine resin.

Full Text Available Trimethoprim (TMP is a dihydrofolate reductase (DHFR inhibitor which prevents the conversion of dihydrofolic acid into tetrahydrofolic acid, resulting in the depletion of the latter and leading to bacterial death. Oral bioavailability of TMP is hindered by both its low solubility and low permeability. This study aims to prepare novel salts of TMP using anionic aminoacids; aspartic and glutamic acid as counter ions in order to improve solubility and dissolution. TMP salts were prepared by lyophilisation and characterized using FT-IR spectroscopy, proton nuclear magnetic resonance (1HNMR, Differential Scanning Calorimetry (DSC and Thermogravimetric analysis (TGA. Both the aminoacids formed salts with TMP in a 1:1 molar ratio and showed a 280 fold improvement in solubility. Investigation of the microbiological activity of the prepared salts against TMP sensitive Escherichia coli showed that the new salts not only retained antibacterial activity but also exhibited higher zone of inhibition which was attributed to improved physicochemical characters such as higher solubility and dissolution. The results are an important finding that could potentially impact on faster onset of antibacterial activity and reduced therapeutic dose when administered to patients. Studies are underway investigating the effect of ion-pairing TMP with aminoacids on the permeability profile of the drug.

Systematic conformational search was carried out for monomers and homohexamers of furanoid β-aminoacids: cis-(S,R) and trans-(S,S) stereoisomers of aminocyclopentane carboxylic acid (ACPC), two different aminofuranuronic-acids (AFU(α) and AFU(β)), their isopropylidene derivatives (AFU(ip)) as well as the key intermediate β-aminotetrahydrofurancarboxylic acid (ATFC). Stereochemistry of the building blocks was chosen to match with that of natural sugar aminoacid (xylose and ribose) precursors. Results show that hexamers of cis furanoid β-aminoacids show great variability: while hydrophobic cyclopentane (cis(ACPC)6), and hydrophilic (cisXylAFU(α/β))6 foldamers favor two different zigzagged conformation as hexamers, the backbone fold turns into a helix in case of (cisATFC)6 (10-helix) and (cisAFU(ip))6 (14-helix). Trans stereochemistry resulted in hexamers exclusively of right-handed helix conformation, (H12(P))6, regardless of their polarity. We found that the preferred oligomeric structure of cis/(S,R)AFU(α/β) is conformationally compatible with β-pleated sheets, while that of the trans/(S,S) units match with α-helices of α-proteins.

Mutations in the main intestinal and kidney luminal neutral aminoacid transporter B(0)AT1 (Slc6a19) lead to Hartnup disorder, a condition that is characterized by neutral aminoaciduria and in some cases pellagra-like symptoms. These latter symptoms caused by low-niacin are thought to result from defective intestinal absorption of its precursor L-tryptophan. Since Ace2 is necessary for intestinal B(0)AT1 expression, we tested the impact of intestinal B(0)AT1 absence in ace2 null mice. Their weight gain following weaning was decreased, and Na(+)-dependent uptake of B(0)AT1 substrates measured in everted intestinal rings was defective. Additionally, high-affinity Na(+)-dependent transport of L-proline, presumably via SIT1 (Slc6a20), was absent, whereas glucose uptake via SGLT1 (Slc5a1) was not affected. Measurements of small intestine luminal aminoacid content following gavage showed that more L-tryptophan than other B(0)AT1 substrates reach the ileum in wild-type mice, which is in line with its known lower apparent affinity. In ace2 null mice, the absorption defect was confirmed by a severalfold increase of L-tryptophan and of other neutral aminoacids reaching the ileum lumen. Furthermore, plasma and muscle levels of glycine and L-tryptophan were significantly decreased in ace2 null mice, with other neutral aminoacids displaying a similar trend. A low-protein/low-niacin diet challenge led to differential changes in plasma aminoacid levels in both wild-type and ace2 null mice, but only in ace2 null mice to a stop in weight gain. Despite the combination of low-niacin with a low-protein diet, plasma niacin concentrations remained normal in ace2 null mice and no pellagra symptoms, such as photosensitive skin rash or ataxia, were observed. In summary, mice lacking Ace2-dependent intestinal aminoacid transport display no total niacin deficiency nor clear pellagra symptoms, even under a low-protein and low-niacin diet, despite gross aminoacid homeostasis alterations.

Full Text Available On the basis of theoretical B3LYP calculations, Yáñez and co-workers (J. Chem. Theory Comput. 2012, 8, 2293 illustrated that beryllium ions are capable of significantly modulating (changing the electronic structures of imidazole. In this computational organic chemistry study, the interaction of this β-aminoacid and five model Lewis acids (BeF1+, Be2+, AlF2(1+, AlF2+, and Al3+ were investigated. Several aspects were addressed: natural bond orbitals, including second order perturbation analysis of intra-molecular charge delocalization and the natural population analysis atomic charges; molecular geometries; selected infrared stretching frequencies (C-N, C-O, and N-H, and selected ¹H-NMR chemical shifts. The data illustrate that this interaction can weaken the H-O bond and goes beyond strengthening the intra-molecular hydrogen bond (N...H-O to cause a spontaneous transfer of the proton to the nitrogen atom in five cases generating zwitterion structures. Many new features are observed. Most importantly, the zwitterion structures include a stabilizing hydrogen bond (N-H...O that varies in relative strength according to the Lewis acid. These findings explain the experimental observations of α-aminoacids (for example: J. Am. Chem. Soc. 2001, 123, 3577 and are the first reported fundamental electronic structure characterization of β-aminoacids in zwitterion form.

The present experiment was carried out with 11 pigs (mean body weight: 53.9 +/- 1.3 kg) fitted with permanent catheters in the portal vein and carotid artery and with an electromagnetic flow probe around the portal vein. They were each subjected to 2 or 3 trials at 3 to 4-day intervals. During each trial the animals received after a previous fasting of 20 h a given amount of a protein-free diet (200 to 1200 g). The blood was collected either continuously for a quantitative determination of amino nitrogen, reducing sugars, urea and ammonia (number of meals 12, mean intake: 727 +/- 60 g) or discontinuously every 30 min between 0 and 8 h after the meal for aminoacid analysis (number of meals 8; mean intake 709 +/- 105 g). A rather constant appearance (2 g/h) of aminoacids in the portal blood was observed throughout the postprandial period. The intestinal absorption of each aminoacid was however variable and represented between 10 and 50% of the daily requirements of the animal during the measuring period (8 h). Glutamine and to a less extent glutamic acid were exceptions as they were taken up by the gut wall from the arterial blood. There was also a marked synthesis of ornithine and citrulline by the latter. Because of the low blood level of urea, there were no apparent exchanges of urea between the blood and the intestine; in contrast, the ammonia absorption represented about 70% of that observed after ingestion of normal protein diets. Most aminoacids are largely taken up by the liver and peripheral tissues, but in the case of alanine the syntheses exceed the uptake.

Because free aminoacids were most probably available in primitive abiotic environments, their metabolism is likely to have provided some of the very first metabolic pathways of life. What were the first enzymatic reactions to emerge? A cladistic analysis of metabolic pathways of the 16 aliphatic aminoacids and 2 portions of the Krebs cycle was performed using four criteria of homology. The analysis is not based on sequence comparisons but, rather, on coding similarities in enzyme properties. The properties used are shared specific enzymatic activity, shared enzymatic function without substrate specificity, shared coenzymes, and shared functional family. The tree shows that the earliest pathways to emerge are not portions of the Krebs cycle but metabolisms of aspartate, asparagine, glutamate, and glutamine. The views of Horowitz (Horowitz, N. H. (1945) Proc. Natl. Acad. Sci. U. S. A. 31, 153-157) and Cordón (Cordón, F. (1990) Tratado Evolucionista de Biologia, Aguilar, Madrid, Spain), according to which the upstream reactions in the catabolic pathways and the downstream reactions in the anabolic pathways are the earliest in evolution, are globally corroborated; however, with some exceptions. These are due to later opportunistic connections of pathways (actually already suggested by these authors). Earliest enzymatic functions are mostly catabolic; they were deaminations, transaminations, and decarboxylations. From the consensus tree we extracted four time spans for aminoacid metabolism development. For some aminoacids catabolism and biosynthesis occurred at the same time (Asp, Glu, Lys, Leu, Ala, Val, Ile, Pro, Arg). For others ultimate reactions that use aminoacids as a substrate or as a product are distinct in time, with catabolism preceding anabolism for Asn, Gln, and Cys and anabolism preceding catabolism for Ser, Met, and Thr. Cladistic analysis of the structure of biochemical pathways makes hypotheses in biochemical evolution explicit and parsimonious.

family members. Analysis of the AA composition of the transgenic lines showed that the level of essential aminoacids increased with a concomitant reduction in proline and glutamine. Both the barley C-hordein and wheat ω-gliadin genes proved successful for RNAi-gene mediated suppression of barley C......C-hordein in barley and ω-gliadins in wheat are members of the prolamins protein families. Prolamins are the major component of cereal storage proteins and composed of non-essential aminoacids (AA) such as proline and glutamine therefore have low nutritional value. Using double stranded RNAi...... silencing technology directed towards C-hordein we obtained transgenic barley lines with up to 94.7 % reduction in the levels of C-hordein protein relative to the parental line. The composition of the prolamin fraction of the barley parental line cv. Golden Promise was resolved using SDS...

The efficiency of utilization of milk aminoacids for body gain in suckling mink kits from small (n = 3), medium (n = 6) and large litters (n = 9) was investigated by using 36 mink dams and their litters for measurements during lactation weeks 1 through 4. Measurements on each dam and litter were...... performed once, hence three dams per litter size each week (n = 9). Individual milk intake of kits was determined, milk samples were collected and kits were killed for determination of aminoacid composition. The most abundant aminoacids in milk were glutamate, leucine and aspartate making up about 40......% of total aminoacids. Branched chained aminoacids made up slightly more than 20% and sulphur containing aminoacids less than 5% of total milk aminoacids. In kit bodies the sum of glutamate, aspartate and leucine made up about 32% of aminoacids, branched chain aminoacids about 16% and sulphur...

Objective: To evaluate the aminoacid profile and quality indices ofClerodendrumvolubile (C. volubile) leaves. Methods:Dried leaves ofC. volubile were blended, defatted and subjected to aminoacid analysis using the technicon sequential multi-sample aminoacid analyzer. The aminoacid quality indices which covers for chemical score, essential aminoacid index, nutritional index, true digestibility, protein digestibility corrected aminoacid score, and digestible indispensable aminoacid score were evaluated using standard formulas. Results: Aminoacid analysis revealed glutamic acid to have the highest concentration, with cysteine having the least. Aspartic acid had the highest chemical score, this was followed by glycine, histidine and arginine, respectively. The least scores were observed in serine and methionine. Glutamic acid had the highest value for true digestibility and protein digestibility corrected aminoacid score, with the least observed in cysteine. Digestible indispensable aminoacid score evaluation showed histidine to have the highest value for infants (birth to 6 months), threonine for children (6 months to 3 years), while isoleucine was observed to have the highest value for older children, adolescents and adults. The essential aminoacid index value was less than 4, while nutritional index value was less than 0.5. Conclusions:These results indicated the leaves ofC. volubile as a potential source of aminoacids in the human diet as portrayed by its aminoacids profile and qualities.

Cinnamaldehyde is a well-established natural antimicrobial compound. It is probable for cinnamaldehyde to react with aminoacid forming Schiff base adduct in real food system. In this paper, 9 such kind of adducts were prepared by the direct reaction of aminoacids with cinnamaldehyde at room temperature. Their antimicrobial activities against Bacillus subtilis, Escherichia coli and Saccharomyces cerevisiae were evaluated with benzoic acid as a reference. The adducts showed a dose-dependent activities against the three microbial strains. Both cinnamaldehyde and their adducts were more active against B. subtilis than on E. coli, and their antimicrobial activities were higher at lower pH. Both cinnamaldehyde and its adducts were more active than benzoic acid at the same conditions. The adduct compound A was non-toxic by primary oral acute toxicity study in mice. However, in situ effect of the adduct compound A against E. coli was a little lower than cinnamaldehyde in fish meat. This paper for the first time showed that the cinnamaldehyde adducts with aminoacids had similar strong antimicrobial activities as cinnamaldehyde, which may provide alternatives to cinnamaldehyde in food to avoid the strong unacceptable odor of cinnamaldehyde.

Full Text Available The ratios of d- versus l-aminoacids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which aminoacids in sedimentary organic matter racemize abiotically between the d- and the l-forms. Based on a heating experiment, we report kinetic parameters for racemization of aspartic acid, glutamic acid, serine, and alanine in bulk sediment from Aarhus Bay, Denmark, taken from the surface, 30 cm, and 340 cm depth below seafloor. Extrapolation to a typical cold deep sea sediment temperature of 3°C suggests racemization rate constants of 0.50×10(-5-11×10(-5 yr(-1. These results can be used in conjunction with measurements of sediment age to predict the ratio of d:l aminoacids due solely to abiotic racemization of the source material, deviations from which can indicate the abundance and turnover of active microbial populations.

Elevated blood branched chain aminoacids (BCAA) are often associated with insulin resistance and type 2 diabetes. One possibility is that under these conditions there is a reduced cellular utilization and/or lower complete oxidation of BCAAs. White adipose tissue (WAT) has become appreciated as a...

The simple phosphoinositide PtdIns3P has been shown to control cell growth downstream of aminoacid signalling and autophagy downstream of aminoacid withdrawal. These opposing effects depend in part on the existence of distinct complexes of Vps34 (vacuolar protein sorting 34), the kinase responsible for the majority of PtdIns3P synthesis in cells: one complex is activated after aminoacid withdrawal to induce autophagy and another regulates mTORC1 (mammalian target of rapamycin complex 1) activation when aminoacids are present. However, lipid-dependent signalling almost always exhibits a spatial dimension, related to the site of formation of the lipid signal. In the case of PtdIns3P-regulated autophagy induction, recent data suggest that PtdIns3P accumulates in a membrane compartment dynamically connected to the endoplasmic reticulum that constitutes a platform for the formation of some autophagosomes. For PtdIns3P-regulated mTORC1 activity, a spatial context is not yet known: several possibilities can be envisaged based on the known effects of PtdIns3P on the endocytic system and on recent data suggesting that activation of mTORC1 depends on its localization on lysosomes.

Structural biominerals are inorganic/organic composites that exhibit remarkable mechanical properties. However, the structure-property relationships of even the simplest building unit--mineral single crystals containing embedded macromolecules--remain poorly understood. Here, by means of a model biomineral made from calcite single crystals containing glycine (0-7 mol%) or aspartic acid (0-4 mol%), we elucidate the origin of the superior hardness of biogenic calcite. We analysed lattice distortions in these model crystals by using X-ray diffraction and molecular dynamics simulations, and by means of solid-state nuclear magnetic resonance show that the aminoacids are incorporated as individual molecules. We also demonstrate that nanoindentation hardness increased with aminoacid content, reaching values equivalent to their biogenic counterparts. A dislocation pinning model reveals that the enhanced hardness is determined by the force required to cut covalent bonds in the molecules.

Arginase is a binuclear manganese metalloenzyme that serves as a therapeutic target for the treatment of asthma, erectile dysfunction, and atherosclerosis. In order to better understand the molecular basis of inhibitor affinity, we have employed site-directed mutagenesis, enzyme kinetics, and X-ray crystallography to probe the molecular recognition of the aminoacid moiety (i.e., the ?-amino and ?-carboxylate groups) of substrate l-arginine and inhibitors in the active site of arginase I. Specifically, we focus on (1) a water-mediated hydrogen bond between the substrate ?-carboxylate and T135, (2) a direct hydrogen bond between the substrate ?-carboxylate and N130, and (3) a direct charged hydrogen bond between the substrate ?-amino group and D183. Aminoacid substitutions for T135, N130, and D183 generally compromise substrate affinity as reflected by increased KM values but have less pronounced effects on catalytic function as reflected by minimal variations of kcat. As with substrate KM values, inhibitor Kd values increase for binding to enzyme mutants and suggest that the relative contribution of intermolecular interactions to aminoacid affinity in the arginase active site is water-mediated hydrogen bond < direct hydrogen bond < direct charged hydrogen bond. Structural comparisons of arginase with the related binuclear manganese metalloenzymes agmatinase and proclavaminic acid amidinohydrolase suggest that the evolution of substrate recognition in the arginase fold occurs by mutation of residues contained in specificity loops flanking the mouth of the active site (especially loops 4 and 5), thereby allowing diverse guanidinium substrates to be accommodated for catalysis.

Isolated chick extensor digitorum communis (EDC) muscles and, in some experiments, rat skeletal muscles were used to study a number of aspects of protein and aminoacid metabolism. (1) Chick EDC muscles synthesize and release large amounts of alanine and glutamine, which indirectly obtain their amino groups from branched-chain aminoacids (BCAA). (2) Acetoacetate or DL-{beta}-hydroxybutyrate (4 mM) decrease (P < 0.01) alanine synthesis and BCAA transamination in EDC muscles from 24-h fasted chicks by decreasing (P < 0.01) intracellular concentrations of pyruvate due to inhibition of glycolysis. (3) Glutamine is extensively degraded in skeletal muscles from both chicks and rats, thus challenging the traditional view that glutamine oxidation is negligible in skeletal muscle. The cytosolic glutamine aminotransferases L and K in the rat and the mitochondrial phosphate-activated glutaminase in the chick play important roles in the conversion of glutamine to {alpha}-ketoglutarate for further oxidation. (4) Although methionine has been reported to be extensively transaminated in rat skeletal muscle preparations in the absence of other aminoacids, transamination of methionine is absent or negligible in chick and rat skeletal muscles in the presence of physiological concentrations of aminoacids. (5) Glutamine at 1.0-15 mM increases (P < 0.01) protein synthesis ({sup 3}H-phenylalanine incorporation), and at 10.0-15.0 mM decreases (P < 0.05) protein degradation ({sup 3}H-phenylalanine release from prelabelled protein in vivo) in EDC muscles from fed chicks as compared to muscles incubated in the absence of glutamine. (6) Acetoacetate or DL-{beta}-hydroxybutyrate (4 mM) has a small but significant inhibitory effect (P < 0.05) on the rate of protein synthesis, but has no effect (P > 0.05) on the rate of protein degradation in EDC muscles from fed chicks.

A study is conducted to determine the aminoacid, fatty acid, and carbohydrate content of breadfruit using high-performance liquid chromatography (HPLC) and gas chromatography (GC). An HPLC method is used for the determination of aminoacids and fatty acids in breadfruit. Representative aminoacid samples are derivatized with phenylisothiocianate and the resulting phenylthiocarbamyl derivatives are separated on a reversed-phase column by gradient elution with a 0.05M ammonium acetate buffer and 0.01M ammonium acetate in acetonitrile-methanol-water (44:10:46, v/v). Representative fatty acid samples are derivatized with phenacyl bromide and the resulting fatty acid phenacyl esters are separated on a reversed-phase column by gradient elution with acetonitrile and water. Aminoacid and fatty acid derivatives are detected by ultraviolet detection at 254 nm. The analysis of the carbohydrates in breadfruit employs a GC method. Carbohydrates are derivatized using trimethylchlorosilane and hexamethyldisilazane to form trimethylsilyl ethers. Compounds in the samples are separated by the temperature programming of a GC using nitrogen as the carrier gas. Percent recoveries of aminoacids, fatty acids, and carbohydrates are 72.5%, 68.2%, and 81.4%, respectively. The starch content of the breadfruit is 15.52 g/100 g fresh weight.

Eccentric exercise results in prolonged muscle damage that may lead to muscle dysfunction. Although inflammation is essential to recover from muscle damage, excessive inflammation may also induce secondary damage, and should thus be suppressed. In this study, we investigated the effect of leucine-enriched essential aminoacids on muscle inflammation and recovery after eccentric contraction. These aminoacids are known to stimulate muscle protein synthesis via mammalian target of rapamycin (mTOR), which, is also considered to alleviate inflammation. Five sets of 10 eccentric contractions were induced by electrical stimulation in the tibialis anterior muscle of male SpragueDawley rats (8-9 weeks old) under anesthesia. Animals received a 1 g/kg dose of a mixture containing 40 % leucine and 60 % other essential aminoacids or distilled water once a day throughout the experiment. Muscle dysfunction was assessed based on isometric dorsiflexion torque, while inflammation was evaluated by histochemistry. Gene expression of inflammatory cytokines and myogenic regulatory factors was also measured. We found that leucine-enriched essential aminoacids restored full muscle function within 14 days, at which point rats treated with distilled water had not fully recovered. Indeed, muscle function was stronger 3 days after eccentric contraction in rats treated with aminoacids than in those treated with distilled water. The aminoacid mix also alleviated expression of interleukin-6 and impeded infiltration of inflammatory cells into muscle, but did not suppress expression of myogenic regulatory factors. These results suggest that leucine-enriched aminoacids accelerate recovery from muscle damage by preventing excessive inflammation.

Two hundred and fifty Cobb-Vantress broiler breeders were used to determine the maintenance requirement and efficiency of utilization of dietary Cys, Tyr, and non-essential aminoacids (AA) in a 21-day experiment. The breeders were fed crystalline aminoacid diets containing graded levels of Cys or Tyr representing 0, 10, 20, 30, and 40% of their suggested requirement level with all other aminoacids maintained at 40% of their suggested requirement level. To determine the non-essential AA maintenance requirement, graded levels of non-essential AA were provided by glutamic acid to represent 12, 19, 26, 33, and 40% of the ideal level of glutamic acid with all other aminoacids maintained at their maintenance requirement level. The total sulfur aminoacid (TSAA) and Phe + Tyr requirements were calculated by combining Cys and Tyr results, respectively, with previously determined Met and Phe, respectively. The slope of Cys, Tyr, and non-essential AA accretion regression line indicated that 29% Cys, 24% TSAA, 21% Tyr, 20% Phe + Tyr, and 9% non-essential AA of crystalline aminoacids were retained. The Cys requirement for zero protein accretion was calculated to be 30.48 mg/d or 17.006 mg/ kgBW(0.75)/d or 75.426 mg/kgCP/d. The TSAA requirement for zero accretion was calculated to be 132.25 mg/b/d, 71.48 mg/kgBW(0.75)/d, and 307.55 mg/kgCP/d. The Tyr requirement for zero protein accretion was calculated to be 65.907 mg/d or 37.233 mg/ kgBW(0.75)/d or 175.566 mg/kgCP/d. The Phe + Tyr requirement for zero protein accretion was calculated to be 352.18 mg/b/d, 190.37 mg/kgBW(0.75)/d, and 749.33 mg/kgCP/d. The non-essential AA requirement for zero protein accretion was calculated to be 3715.194 mg/d or 2003.155 mg/kgBW(0.75)/d or 9452.954 mg/kgCP/d.

Conformationally restricted aminoacids are important components in peptidomimetics and drug design. Herein, we describe the synthesis of a novel, non-proteinogenic constrained delta aminoacid containing a cyclobutane ring, cis-3(aminomethyl)cyclobutane carboxylic acid (ACCA). The synthesis of the target aminoacid was achieved in seven steps, with the key reaction being a base induced intramolecular nucleophilic substitution. A small library of dipeptides was prepared through the coupling of ACCA with proteinogenic aminoacids.

We report the method of LC/ESI-MS analysis of underivatized aminoacids with corresponding mass spectrum and fragmentation patterns. Diagnostic product ions determined by mass spectrometry can support the qualitative identification and quantitative estimation of individual aminoacids. Therefore, the optimization of chromatographic separation using the ion-pairing reagent (i.e., Nonafluoropentanoic acid, NFPA) is useful for the evaluation of target aminoacid and for further compound-specific nitrogen isotope studies of aminoacids.

The solute rejection versus concentration behaviour of five different aminoacids has been investigated using a Nitto Denko NTR7450 nanofiltration membrane. The experimental data for aminoacid rejection was also compared against a combined steric and charge rejection model. At its isoelectric point, lysine was effectively neutral and its behaviour was well described by the model incorporating a steric function only. For phenylalanine, the combined model was found to fit the data well. In contrast there was poor agreement between the model and rejection data for glutamine, glutamic acid and glycine whose rejection values at first increased with concentration. This result implied that another governing process was in operation. Dimerisation as an explanation for the observed phenomena was also investigated. Size analysis of aminoacid molecules as a function of the prevailing concentration using dynamic light scattering was limited but showed no evidence of dimerisation. This data was supported by osmotic pressure measurements which demonstrated no evidence of non-linearity in the relation between osmotic pressure and concentration.

A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than the corresponding DNA or RNA strands, and exhibit increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a group consisting...

Nanocomposites of graphene oxide and gold nanoparticles (GO/GNPs) were synthesized for label-free detections of aminoacids. Interactions between the composites and aminoacids were investigated by both naked-eye observation and optical absorption spectroscopy. The GO/GNPs composites displayed apparent color changes and absorption spectra changes in presences of aminoacids including glutamate, aspartate, and cysteine. The interaction mechanisms of the composites and aminoacids were discussed and explored with sulfhydryl groups and non-α-carboxylic groups on the aminoacids. Sensing properties of the composites were tested, while pure gold particles were used as the control. The results suggested that the GO/GNPs composites had better linearity and stability in dose-dependent responses to the aminoacids than those of the particles, especially in detections for acidicaminoacids. Therefore, the nanocomposites platform can provide a convenient and efficient approach for label-free optical detections of important molecules such as aminoacids.

The adsorption isotherms of glycine,alanine and oxidized glutathion on strong acid cation and strong base anion exchange resins from aqueous solutions were measured and the superequivalent adsorptions of glycine and alanine observed.The infrared spectra of glycine adsorbed on the cation and the anion exchange resins,001×7 and 201×7,were measured.From these results,it is concluded that the aminoacid adsorption on the ion exchange resin proceeds not only through ion exchange and proton transfer mechanisms,but also through aminecarboxylate interaction between the adsorbed aminoacid molecules,and the formation of second layer of aminoacid molecules is the mechanism of superequivalent adsorption of aminoacid,the carboxylate or amine groups of the first layer of aminoacid molecules on the ion exchange resin act as the exchange sites for the second layer of aminoacid molecules.

Many living organisms contain biominerals and composites with finely tuned properties, reflecting a remarkable level of control over the nucleation, growth and shape of the constituent crystals. Peptides and proteins play an important role in achieving this control. Using in situ AFM we find that site-specific binding of aminoacid residues to surface steps changes the step-edge free energies, giving rise to direction-specific binding energies unique to individual aminoacid enantiomers and leading to chiral modifications that propagate from atomic length scales to macroscopic length scales. Molecular modeling studies support an energetic basis for the differences in binding. Our results emphasize that the mechanism under-lying crystal modification through organic molecules is best understood by considering both stereochemical recognition as well as the effects of binding on the interfacial energies of the growing crystal.

Full Text Available Aminoacids play fundamental roles in a multitude of functions including protein synthesis, hormone metabolism, nerve transmission, cell growth, production of metabolic energy, nucleobase synthesis, nitrogen metabolism and urea biosynthesis. Selaginella as a member of the lycophytes is part of an ancient lineage of vascular plants that had arisen ~400 million years ago. In angiosperms, which have attracted most of the attention for nutrient distribution so far, we have been able to identify many of the key transporters for nitrogen. Their role is not always fully clear, thus an analysis of Selaginella as a representative of an ancient vascular plant may help shedding light on the evolution and function of these diverse transporters. Here we analyze the genes for transporters involved in cellular uptake of aminoacids present in the Selaginella genome.

Aminoacids play fundamental roles in a multitude of functions including protein synthesis, hormone metabolism, nerve transmission, cell growth, production of metabolic energy, nucleobase synthesis, nitrogen metabolism, and urea biosynthesis. Selaginella as a member of the lycophytes is part of an ancient lineage of vascular plants that had arisen ∼400 million years ago. In angiosperms, which have attracted most of the attention for nutrient transport so far, we have been able to identify many of the key transporters for nitrogen. Their role is not always fully clear, thus an analysis of Selaginella as a representative of an ancient vascular plant may help shed light on the evolution and function of these diverse transporters. Here we annotated and analyzed the genes encoding putative transporters involved in cellular uptake of aminoacids present in the Selaginella genome.

Acetohydroxyacid synthase (AHAS) (EC 4.1.3.18) is a target of commercially available herbicides such as sulfonylurea, imidazolinone, and triazolopyrimidine. In plants and microorganisms, AHAS catalyzes the first common reaction in the biosynthesis pathways leading to leucine, isoleucine and valine. Intensive studies using different approaches - including site-directed mutagenesis, molecular modeling and structural analysis - on plant AHAS-s have contributed to the understanding of the herbicide-AHAS interaction. Knowledge of the critical roles of aminoacid residues of plant AHAS in conferring herbicide resistance will enable the creation of new herbicide-tolerant AHAS which could be used to develop herbicide-resistant transgenic plants. Moreover, such information will also elucidate design strategies for more efficient herbicides that could also kill weeds resistant to previously used AHAS-inhibiting herbicides. In this review, we summarize the results of intensive searches for aminoacid residues and their substitutions that confer herbicide resistance in tobacco AHAS.

The authors have detected atypical paecilomycosis-associated myocarditis with impaired aminoacid exchange and pain syndrome for the first time. At first, pain occurs in the chest and radiates into the axilla, to the left arm to the finger tips, by paralyzing the arm. In some patients, pain manifests itself in both arms with radiation to the belly, by accompanying by fainting. The skin is wet, cold; the pulse is frequent and of poor volume and difficult-to-count. Heart pain spreads into the armpit and down the arm, by making the fingers numb. Attempts to use current analgesics (movalis, sirdalud, nimesil, morphine) in combination with fungicides (diflucan, mycosist, orungal) have failed to yield positive results. The homeopathic drug Latrodectus mactans, prepared from caracurt venom, in combination with the authors' designed diet and other homeopathic agents have relieved pain syndrome and normalized aminoacid exchange, which offered possibilities for successful surgical treatment for echinococcosis with later recovery.

Full Text Available The effective atomic number and effective electron density in aminoacids are of significant interest due to their use in various applications. The energy absorption buildup factors, exposure buildup factors, effective atomic numbers, and electron densities of essential aminoacids such as Leucine (C6H13NO2, Lysine (C6H14N2O2, Methionine (C5H11NO2S, Phenylalanine (C9H11NO2, Threonine (C4H9NO3, Tryptophan (C11H12N2O2, Valine (C5H11NO2, Arginine (C6H14N4O2, and Histidine (C6H9N3O2 were determined theoretically in the energy range 0.015–15 MeV.

This paper describes the most important articles that have been published on aminoacid analysis using CE during the period from June 2009 to May 2011 and follows the format of the previous articles of Smith (Electrophoresis 1999, 20, 3078-3083), Prata et al. (Electrophoresis 2001, 22, 4129-4138) and Poinsot et al. (Electrophoresis 2003, 24, 4047-4062; Electrophoresis 2006, 27, 176-194; Electrophoresis 2008, 29, 207-223; Electrophoresis 2010, 31, 105-121). We present new developments in aminoacid analysis with CE, which are reported describing the use of lasers or light emitting diodes for fluorescence detection, conductimetry electrochemiluminescence detectors, mass spectrometry applications, and lab-on-a-chip applications using CE. In addition, we describe articles concerning clinical studies and neurochemical applications of these techniques.

What are proteins made from, as the working parts of the living cells protein machines? To answer this question, we need a technology to disassemble proteins onto elementary func-tional details and to prepare lumped description of such details. This lumped description might have a multiple material realization (in aminoacids). Our hypothesis is that informational approach to this problem is possible. We propose a way of hierarchical classification that makes the primary structure of protein maximally non-random. The first steps of the suggested research program are realized: the method and the analysis of optimal informational protein binary alphabet. The general method is used to answer several specific questions, for example: (i) Is there a syntactic difference between Globular and Membrane proteins? (ii) Are proteins random sequences of aminoacids (a long discussion)? For these questions, the answers are as follows: (i) There exists significant syntactic difference between Globular and Membrane proteins,...

The new revised version of the Standard Tables of Food Composition in Japan (STFCJ 2015) will be published in 2015. The aim of the present paper is to share information on issues we have encountered during the revision. New analytical data on aminoacid composition will be provided for approximately 230 foods, fatty acid composition for approximately 140 foods, and available carbohydrate (starch, glucose, fructose, sucrose, maltose, and lactose) composition for approximately 340 foods. These data will be published separately as three supplements to the STFCJ 2015: aminoacid tables, fatty acid tables, and available carbohydrate tables. Available carbohydrate tables will also provide polyol (sorbitol and mannitol) and organic acid (acetic acid, lactic acid, citric acid, etc.) data. In the supplements, aminoacid content will be adjusted for protein content calculated as reference nitrogen multiplied by a nitrogen to protein conversion factor, and fatty acid content adjusted for extractable lipid content, as in previous revisions. Available carbohydrate content, however, will be adjusted for water content. Values of protein content calculated as the sum of aminoacid residues , lipid content expressed as triacylglycerol equivalents of fatty acids , and available carbohydrate content will appear in the main tables of the STFCJ 2015. Protein, fat and available carbohydrate contents were significantly decreased when the preferred analytical methods of FAO were applied instead of the acceptable methods. Online publication of Japanese and English versions of these tables, reference materials, and a retrievable food composition database is planned.

The cytochrome c' are electron transport proteins widely distributed in photosynthetic and aerobic bacteria. We report the aminoacid sequences of the proteins from 12 different bacterial species, and we show by sequences that the cytochromes c-556 from 2 different bacteria are structurally related to the cytochromes c'. Unlike the mitochondrial cytochromes c, the heme binding site in the cytochromes c' and c-556 is near the COOH terminus. The cytochromes c-556 probably have a methionine sixt...

A series of novel nanosized aminoacid-polyoxometalate compounds were successfully synthesized using a low temperature solid-state chemical reaction method. Their compositions, structures, morphologies, photochromic properties were characterized by ICP-AES/MS, TG/DTA, FTIR, XRD, SEM and UV-Vis diffuse reflectance spectra (DRS), respectively. The elemental analysis results showed that the compounds ((HThr)7PMo12O42•4H2O, (HTyr)7PMo12O42Â.5H2O, (HSer)7PMo12O42•5H2O and (HGlu)7PMo12O42•4H2O) were obtained. The analyses of the TG/DTA, XRD and FTIR confirmed that the four compounds are new phases different from the corresponding reactants and they are composed of the polyoxometalate anions and the corresponding protonated aminoacids, respectively. Observation of the SEM revealed that the particle shape (e.g. (HThr)7PMo12O42Â.4H2O nanoplates, (HTyr)7PMo12O42•5H2O nanorods, (HSer)7PMo12O42•5H2O and (HGlu)7PMo12O42•4H2O nanoparticles) depended strongly on the structures of aminoacids. This implied that the aminoacids can play a structural template agent role in synthesis of the Silverton-type polyoxometalate compounds. After irradiated with ultraviolet light, these samples all exhibited photochromism. Their photochromic mechanism may be explained based on Yamase's photochromic model. These photochromic compounds could be applied to the field of photosensitive materials.

Single-nucleotide polymorphisms (SNPs) are recognized as one kind of major genetic variants in population scale. However, polymorphisms at the proteome level in population scale remain elusive. In the present study, we named aminoacid variances derived from SNPs within coding regions as single aminoacid polymorphisms (SAPs) at the proteome level, and developed a pipeline of non-targeted and targeted proteomics to identify and quantify SAP peptides in human plasma. The absolute concentrations of three selected SAP-peptide pairs among 290 Asian individuals were measured by selected reaction monitoring (SRM) approach, and their associations with both obesity and diabetes were further analyzed. This work revealed that heterozygotes and homozygotes with various SAPs in a population could have different associations with particular traits. In addition, the SRM approach allows us for the first time to separately measure the absolute concentration of each SAP peptide in the heterozygotes, which also shows different associations with particular traits.%Single-nucleotide polymorphisms (SNPs) are recognized as one kind of major genetic variants in population scale.However,polymorphisms at the proteome level in population scale remain elusive.In the present study,we named aminoacid variances derived from SNPs within coding regions as single aminoacid polymorphisms (SAPs) at the proteome level,and developed a pipeline of non-targeted and targeted proteomics to identify and quantify SAP peptides in human plasma.The absolute concentrations of three selected SAP-peptide pairs among 290 Asian individuals were measured by selected reaction monitoring (SRM) approach,and their associations with both obesity and diabetes were further analyzed.This work revealed that heterozygotes and homozygotes with various SAPs in a population could have different associations with particular traits.In addition,the SRM approach allows us for the first time to separately measure the absolute

Bioleaching has become a major production process for copper contributing currently to around 15 % of the world wide copper production. However, non-sulfidic and/or complex ores are still not efficiently minable by conventional methods. In this study, we investigated the effect of copper complexing molecules such as aminoacids on Cu{sup 2+} and S{sup 2-} solubilization from covellite.

To understand the relationship between protein sequence and structure, this work extends the knob-socket model in an investigation of β-sheet packing. Over a comprehensive set of β-sheet folds, the contacts between residues were used to identify packing cliques: sets of residues that all contact each other. These packing cliques were then classified based on size and contact order. From this analysis, the two types of four-residue packing cliques necessary to describe β-sheet packing were characterized. Both occur between two adjacent hydrogen bonded β-strands. First, defining the secondary structure packing within β-sheets, the combined socket or XY:HG pocket consists of four residues i, i+2 on one strand and j, j+2 on the other. Second, characterizing the tertiary packing between β-sheets, the knob-socket XY:H+B consists of a three-residue XY:H socket (i, i+2 on one strand and j on the other) packed against a knob B residue (residue k distant in sequence). Depending on the packing depth of the knob B residue, two types of knob-sockets are found: side-chain and main-chain sockets. The aminoacid composition of the pockets and knob-sockets reveal the sequence specificity of β-sheet packing. For β-sheet formation, the XY:HG pocket clearly shows sequence specificity of aminoacids. For tertiary packing, the XY:H+B side-chain and main-chain sockets exhibit distinct aminoacid preferences at each position. These relationships define an aminoacid code for β-sheet structure and provide an intuitive topological mapping of β-sheet packing.

Multinuclear metal ion clusters, coordinated by proteins, catalyze various critical biological redox reactions, including water oxidation in photosynthesis, and nitrogen fixation. Designed metalloproteins featuring synthetic metal clusters would aid in the design of bio-inspired catalysts for various applications in synthetic biology. The design of metal ion-binding sites in a protein chain requires geometrically constrained and accurate placement of several (between three and six) polar and/or charged aminoacid side chains for every metal ion, making the design problem very challenging to address. Here, we describe a general computational method to redesign oligomeric interfaces of symmetric proteins for the purpose of creating novel multinuclear metalloproteins with tunable geometries, electrochemical environments, and metal cofactor stability via first and second-shell interactions. The method requires a target symmetric organometallic cofactor whose coordinating ligands resemble the side chains of a natural or unnatural aminoacid and a library of oligomeric protein structures featuring the same symmetry as the target cofactor. Geometric interface matches between target cofactor and scaffold are determined using a program that we call symmetric protein recursive ion-cofactor sampler (SyPRIS). First, the aminoacid-bound organometallic cofactor model is built and symmetrically aligned to the axes of symmetry of each scaffold. Depending on the symmetry, rigid body and inverse rotameric degrees of freedom of the cofactor model are then simultaneously sampled to locate scaffold backbone constellations that are geometrically poised to incorporate the cofactor. Optionally, backbone remodeling of loops can be performed if no perfect matches are identified. Finally, the identities of spatially proximal neighbor residues of the cofactor are optimized using Rosetta Design. Selected designs can then be produced in the laboratory using genetically incorporated unnatural

Permeability coefficients for aminoacid classes, including neutral, polar, hydrophobic, and charged species, were measured and compared with values for other ionic solutes such as phosphate. The rates of efflux of glycine, lysine, phenylalanine, serine and tryptophan were determined after they were passively entrapped in large unilamellar vesicles (LUVs) composed of egg phosphatidylcholine (EPC) or dimyristoylphosphatidylcholine (DMPC). The following permeability coefficients were obtained for: glycine, 5.7 x 10(-12) cm s-1 (EPC), 2.0 x 10(-11) cm s-1 (DMPC); serine, 5.5 x 10(-12) cm s-1 (EPC), 1.6 x 10(-11) cm s-1 (DMPC); lysine, 5.1 x 10(-12) cm s-1 (EPC), 1.9 x 10(-11) cm s-1 (DMPC); tryptophan, 4.1 x 10(-10) cm s-1 (EPC); and phenylalanine, 2.5 x 10(-10) cm s-1 (EPC). Decreasing lipid chain length increased permeability slightly, while variations in pH had only minor effects on the permeability coefficients of the aminoacids tested. Phosphate permeability was in the range of 10(-12)-10(-13) cm s-1 depending on the pH of the medium. The values for the polar and charged aminoacids were surprisingly similar to those previously measured for monovalent cations such as sodium and potassium, which are in the range of 10(-12)-10(-13) cm s-1, depending on conditions and the lipid species used. This observation suggests that the permeation rates for the neutral, polar and charged aminoacids are controlled by bilayer fluctuations and transient defects, rather than partition coefficients and Born energy barriers. The results are relevant to the permeation of certain peptides into lipid bilayers during protein translocation and membrane biogenesis.

The aromatic aminoacid hydroxylases phenylalanine hydroxylase, tyrosine hydroxylase, and tryptophan hydroxylase are homotetramers, with each subunit containing a homologous catalytic domain and a divergent regulatory domain. The solution structure of the regulatory domain of tyrosine hydroxylase establishes that it contains a core ACT domain similar to that in phenylalanine hydroxylase. The isolated regulatory domain of tyrosine hydroxylase forms a stable dimer, while that of phenylalanine h...

We develop a simple optimization procedure for assigning binary values to the aminoacids. The binary values are determined by a maximization of the degree of pattern conservation in groups of closely related protein sequences. The maximization is carried out at fixed composition. For compositions approximately corresponding to an equipartition of the residues, the optimal encoding is found to be strongly correlated with hydrophobicity. The stability of the procedure is demonstrated. Our calculations are based upon sequences in the SWISS-PROT database.

The title of our project is “Aminoacid-sensing ion channels in plants”. Its goals are two-fold: to determine the molecular functions of glutamate receptor-like (GLR) proteins, and to elucidate their biological roles (physiological or developmental) in plants. Here is our final technical report. We were highly successful in two of the three aims, modestly successful in the third.

The thermal condensation of formamide in the presence of mineral borates is reported. The products afforded are precursors of nucleic acids, aminoacids derivatives and carboxylic acids. The efficiency and the selectivity of the reaction was studied in relation to the elemental composition of the 18 minerals analyzed. The possibility of synthesizing at the same time building blocks of both genetic and metabolic apparatuses, along with the production of aminoacids, highlights the interest of the formamide/borate system in prebiotic chemistry.

Aminoacid precursors in protected amino alcohol form are important synthons that can be used as building-blocks for the hemisynthesis of non-natural aminoacids.Serine can be used as a common starting material for the synthesis of such compounds differently protected.Particularly,protected amino alcohols bearing an ethynyl and/or an iodoethynyl group can be used in cross-couplings,in 1,3-dipolar cycloadditions and/or in Nozaki-Hiyama-Kishi type reactions.We thus demonstrated that the efficiently protected amino alcohols derived from serine can be coupled to a sugar derivative by an indium mediated alkynylation reaction.The conditions of this coupling are compatible with such functionalized derivatives and allow envisaging an access to C-glycosylated aminoacids.

Full Text Available The nutritional status in chronic kidney disease (CKD patients is a predictor of prognosis during the first period of dialysis. Serum albumin is the most commonly used nutritional marker. Another index is plasma aminoacid profile. Of these, the plasma levels of branched chain aminoacids (BCAA, especially valine and leucine, correlate well with nutritional status. Plasma BCAAs were evaluated along with albumin and C-reactive protein in 15 patients of early stages of CKD and 15 age- and sex-matched healthy controls. A significant decrease in plasma valine, leucine and albumin levels was observed in CKD patients when compared with the controls (P <0.05. No significant difference in C-reactive protein (CRP levels was observed between the two groups. Malnutrition seen in our CKD patients in the form of hypoalbuminemia and decreased concentrations of BCAA points to the need to evaluate the nutritional status in the early stages itself. Simple measures in the form of aminoacid supplementation should be instituted early to decrease the morbidity and mortality before start of dialysis in these patients.

Full Text Available L-Aminoacid oxidases are flavoenzymes which catalyze the stereospecific oxidative deamination of an L-aminoacid substrate to a corresponding a-ketoacid with hydrogen peroxide and ammonia production. These enzymes, which are widely distributed in many different organisms, exhibit a marked affinity for hydrophobic aminoacids, including phenylalanine, tryptophan, tyrosine, and leucine. Snake venom LAAO induces platelet aggregation and cytotoxicity in various cancer cell lines. The enzyme has antibacterial activity inhibiting the growth of Gram-positive (Bacillus subtilis and Gram-negative (Escherichia coli bacteria. Specific substrates for the isolated protein are L-phenylalanine, L-tryptophan, L-methionine and L-leucine. The enzyme is stable at low temperatures (−20 ºC, −70 ºC and loses its activity by heating at 70 ºC. These enzymes are postulated to be toxins that may be involved in the allergic inflammatory response and specifically associated with mammalian endothelial cells damage. However, in the last decade these enzymes have become an interesting subject for pharmacological, structural and molecular characterizations. Structural and functional investigations of these enzymes can contribute to the advancement of toxinology and to the elaboration of novel therapeutic agents.

The process of natural selection acts both on individual organisms within a population and on individual cells within an organism as they develop into cancer. In this work, we have taken a first step toward understanding the differences in selection pressures exerted on the human genome under these disparate circumstances. Focusing on single aminoacid substitutions, we have found that cancer-related mutations (CRMs) are frequent in evolutionarily conserved sites, whereas single aminoacid polymorphisms (SAPs) tend to appear in sites having a more relaxed evolutionary pressure. Those CRMs classed as cancer driver mutations show greater enrichment for conserved sites than passenger mutations. Consistent with this, driver mutations are enriched for sites annotated as key functional residues and their neighbors, and are more likely to be located on the surface of proteins than expected by chance. Overall the pattern of CRM and polymorphism is remarkably similar, but we do see a clear signal indicative of diversifying selection for disruptive aminoacid substitutions in the cancer driver mutations. The ultimate consequence of the appearance of those mutations must be advantageous for the tumor cell, leading to cell population-growth and migration events similar to those seen in natural ecosystems.

Full Text Available Several secondary structures, such as π-helix and left-handed helix, have been frequently identified at protein ligand-binding sites. A secondary structure is considered to be constrained to a specific region of dihedral angles. However, a comprehensive analysis of the correlation between main chain dihedral angles and ligand-binding sites has not been performed. We undertook an extensive analysis of the relationship between dihedral angles in proteins and their distance to ligand-binding sites, frequency of occurrence, molecular potential energy, aminoacid composition, van der Waals contacts, and hydrogen bonds with ligands. The results showed that the values of dihedral angles have a strong preference for ligand-binding sites at certain regions in the Ramachandran plot. We discovered that aminoacids preceding the ligand-prefer ϕ/ψ box residues are exposed more to solvents, whereas aminoacids following ligand-prefer ϕ/ψ box residues form more hydrogen bonds and van der Waals contacts with ligands. Our method exhibited a similar performance compared with the program Ligsite-csc for both ligand-bound structures and ligand-free structures when just one ligand-binding site was predicted. These results should be useful for the prediction of protein ligand-binding sites and for analysing the relationship between structure and function.

We present here selected results recently obtained on the molecular characterization of aminoacids adsorption on oxide minerals and their further polymerization by thermal activation, in the general frame of assessing Bernal's hypothesis on the origin of biopolymers on mineral surfaces. Adsorption mechanisms may be identified by a combination of vibrational spectroscopy, 13C solid-state NMR, and molecular modeling. Depending on a particular aminoacid, the oxide surface investigated, and the water activity during adsorption (i.e., whether it is carried out from the gas phase or from an aqueous solution), contributions from electrostatic adsorption, outer-sphere and inner-sphere (coordination) complexes may be observed. These mechanisms result in significant adsorption selectivities from equimolar mixtures of different aminoacids. Upon thermal activation at moderate temperatures (150-160 °C), clean polymerization events occur and can easily be observed by thermogravimetric analysis. There are some hints of selectivity in this step too. The water activity during thermal treatment plays an important role for the thermodynamics of polymerization.

Forty-three phase diagrams of ternary system concerning rare earth salts, α-aminoacids and water, which were constructed by phase equilibrium methods, were expounded. The influences of the factors such as cations, anions, the structure of aminoacids, temperature on the phase diagrams were discussed. Under the guidance of phase equilibrium results, over 150 new solid complexes were prepared. IR, reflecting, UV, FS, and Raman spectra for these complexes were investigated and the regularity of “tripartite effect”, “tetrad effect”, “Nephelanxetic effect”, “Oddo-Harkins” was observed. Thermal decomposition processes of the complexes were confirmed. Based on the comparison with the known crystal structures of rare earth-aminoacid-complexes, an estimation method for predicting the crystal structure data of series complexes was founded. The constant volume combustion energies of the complexes were determined by RBC-1 type rotating bomb calorimeter. The standard enthalpies of combustion and standard enthalpies of formation were calculated for these complexes.

Protein is the most expensive part of fish diets and supplies aminoacids (AA) for energy, growth, protein synthesis and as substrates for key metabolic pathways. Functional AA is a term used to describe AA that are involved in cellular processes apart from protein synthesis. A deficiency, or imbalance, in functional AA may impair body metabolism and homeostasis. Recent years have seen an increased interest in AA to increase disease resistance, immune response, reproduction, behavior and more. This has led to a boost of commercially available functional fish feeds that aim to optimize fish performance and quality of the product. This review aim to collect recent findings of functional AA and of how they may improve fish health and welfare. It will focus on functional properties of some of the most studied AA, namely arginine, glutamine, glutamate, tryptophan, sulfur aminoacids (methionine, cysteine and taurine), histidine and branched chain aminoacids. Where information is not available in fish, we will point towards functions known in animals and humans, with possible translational functions to fish.

Prolonged oral creatine administration resulted in remarkable neuroprotection in experimental models of brain stroke. However, because of its polar nature creatine has poor ability to penetrate the blood-brain barrier (BBB) without specific creatine transporter (CRT). Thus, synthesis of hydrophobic derivatives capable of crossing the BBB by alternative pathway is of great importance for the treatment of acute and chronic neurological diseases including stroke, traumatic brain injury and hereditary CRT deficiency. Here we describe synthesis of new hybrid compounds-creatinyl aminoacids, their neuroprotective activity in vivo and stability to degradation in different media. The title compounds were synthesized by guanidinylation of corresponding sarcosyl peptides or direct creatine attachment using isobutyl chloroformate method. Addition of lipophilic counterion (p-toluenesulfonate) ensures efficient creatine dissolution in DMF with simultaneous protection of guanidino group towards intramolecular cyclization. It excludes the application of expensive guanidinylating reagents, permits to simplify synthetic procedure and adapt it to large-scale production. The biological activity of creatinyl aminoacids was tested in vivo on ischemic stroke and NaNO(2) -induced hypoxia models. One of the most effective compounds-creatinyl-glycine ethyl ester increases life span of experimental animals more than two times in hypoxia model and has neuroprotective action in brain stroke model when applied both before and after ischemia. These data evidenced that creatinyl aminoacids can represent promising candidates for the development of new drugs useful in stroke treatment.

Mass spectrometry-based serum metabolic profiling is a promising tool to analyse complex cancer associated metabolic alterations, which may broaden our pathophysiological understanding of the disease and may function as a source of new cancer-associated biomarkers. Highly standardized serum samples of patients suffering from colon cancer (n = 59) and controls (n = 58) were collected at the University Hospital Leipzig. We based our investigations on aminoacid screening profiles using electrospray tandem-mass spectrometry. Metabolic profiles were evaluated using the Analyst 1.4.2 software. General, comparative and equivalence statistics were performed by R 2.12.2. 11 out of 26 serum aminoacid concentrations were significantly different between colorectal cancer patients and healthy controls. We found a model including CEA, glycine, and tyrosine as best discriminating and superior to CEA alone with an AUROC of 0.878 (95% CI 0.815-0.941). Our serum metabolic profiling in colon cancer revealed multiple significant disease-associated alterations in the aminoacid profile with promising diagnostic power. Further large-scale studies are necessary to elucidate the potential of our model also to discriminate between cancer and potential differential diagnoses. In conclusion, serum glycine and tyrosine in combination with CEA are superior to CEA for the discrimination between colorectal cancer patients and controls.

Although many aminoacid substitution matrices have been developed, it has not been well understood which is the best for similarity searches, especially for remote homology detection. Therefore, we collected information related to existing matrices, condensed it and derived a novel matrix that can detect more remote homology than ever. Using principal component analysis with existing matrices and benchmarks, we developed a novel matrix, which we designate as MIQS. The detection performance of MIQS is validated and compared with that of existing general purpose matrices using SSEARCH with optimized gap penalties for each matrix. Results show that MIQS is able to detect more remote homology than the existing matrices on an independent dataset. In addition, the performance of our developed matrix was superior to that of CS-BLAST, which was a novel similarity search method with no aminoacid matrix. We also evaluated the alignment quality of matrices and methods, which revealed that MIQS shows higher alignment sensitivity than that with the existing matrix series and CS-BLAST. Fundamentally, these results are expected to constitute good proof of the availability and/or importance of aminoacid matrices in sequence analysis. Moreover, with our developed matrix, sophisticated similarity search methods such as sequence-profile and profile-profile comparison methods can be improved further. Newly developed matrices and datasets used for this study are available at http://csas.cbrc.jp/Ssearch/.

Deleterious interactions among genes cause reductions in fitness of interpopulation hybrids (hybrid breakdown). Identifying genes involved in hybrid breakdown has proven difficult, and few studies have addressed the molecular basis of this widespread phenomenon. Because proper function of the mitochondrial electron transport system (ETS) requires a coadapted set of nuclear and mitochondrial gene products, ETS genes present an attractive system for studying the evolution of coadapted gene complexes within isolated populations and the loss of fitness in interpopulation hybrids. Here we show the effects of single aminoacid substitutions in cytochrome c (CYC) on its functional interaction with another ETS protein, cytochrome c oxidase (COX) in the intertidal copepod Tigriopus californicus. The individual and pairwise consequences of three naturally occurring aminoacid substitutions in CYC are examined by site-directed mutagenesis and found to differentially effect the rates of CYC oxidation by COX variants from different source populations. In one case, we show that interpopulation hybrid breakdown in COX activity can be attributed to a single naturally occurring aminoacid substitution in CYC.

The first steps of hydration of the protonated aromatic aminoacids phenylalanine, tryptophan, and tyrosine were studied experimentally employing a mass spectrometer equipped with a drift cell to examine the sequential addition of individual water molecules in equilibrium experiments and theoretically by a combination of molecular mechanics and electronic structure calculations (B3LYP/6-311++G**) on the three aminoacid systems including up to five water molecules. It is found that both the ammonium and carboxyl groups offer good water binding sites with binding energies of the order of 13 kcal/mol for the first water molecule. Subsequent water molecules bind less strongly, in the range of 7-11 kcal/mol for the second through fifth water molecules. The ammonium group is able to host up to three water molecules and the carboxyl group one water molecule before additional water molecules bind either to the aminoacid side chain as in tyrosine or to already-bound water in a second solvation shell around the ammonium group. Reasons for the surprisingly high water affinity of the neutral carboxyl group, comparable to that of the charge-carrying ammonium group, are found to be high intrinsic hydrophilicity, favorable charge-dipole alignment, and--for the case of multiply hydrated species--favorable dipole-dipole interaction among water molecules and the lack of alternative fully exposed hydration sites.

We attempt to set a mathematical foundation of immunology and aminoacid chains. To measure the similarities of these chains, a kernel on strings is defined using only the sequence of the chains and a good aminoacid substitution matrix (e.g. BLOSUM62). The kernel is used in learning machines to predict binding affinities of peptides to human leukocyte antigens DR (HLA-DR) molecules. On both fixed allele (Nielsen and Lund 2009) and pan-allele (Nielsen et.al. 2010) benchmark databases, our algorithm achieves the state-of-the-art performance. The kernel is also used to define a distance on an HLA-DR allele set based on which a clustering analysis precisely recovers the serotype classifications assigned by WHO (Nielsen and Lund 2009, and Marsh et.al. 2010). These results suggest that our kernel relates well the chain structure of both peptides and HLA-DR molecules to their biological functions, and that it offers a simple, powerful and promising methodology to immunology and aminoacid chain studies.

Whey protein (WP) supplements have received increasing attention by consumers due to the high nutritional value of the proteins and aminoacids they provide. However, some WP supplements may not contain the disclosed amounts of the ingredients listed on the label, compromising the nutritional quality and the effectiveness of these supplements. The aim of this study was to evaluate and compare the contents of total protein (TP), α-lactalbumin (α-LA), β-lactoglobulin (β-LG), free essential aminoacids (free EAA), and free branched-chain aminoacids (free BCAA), amongst different WP supplements produced by U.S. and Brazilian companies. Twenty commercial brands of WP supplements were selected, ten manufactured in U.S. (WP-USA) and ten in Brazil (WP-BRA). The TP was analyzed using the Kjeldahl method, while α-LA, β-LG, free EAA, and free BCAA were analyzed using HPLC system. There were higher (p 0.05) in the content of free EAA between WP-USA and WP-BRA. Amongst the 20 brands evaluated, four WP-USA and seven WP-BRA had lower (p < 0.05) values of TP than those specified on the label. In conclusion, the WP-USA supplements exhibited better nutritional quality, evaluated by TP, α-LA, β-LG, and free BCAA when compared to WP-BRA.

In this article, we categorize presently available experimental and theoretical knowledge of various physicochemical and biochemical features of aminoacids, as collected in the AAindex database of known 544 aminoacid (AA) indices. Previously reported 402 indices were categorized into six groups using hierarchical clustering technique and 142 were left unclustered. However, due to the increasing diversity of the database these indices are overlapping, therefore crisp clustering method may not provide optimal results. Moreover, in various large-scale bioinformatics analyses of whole proteomes, the proper selection of aminoacid indices representing their biological significance is crucial for efficient and error-prone encoding of the short functional sequence motifs. In most cases, researchers perform exhaustive manual selection of the most informative indices. These two facts motivated us to analyse the widely used AA indices. The main goal of this article is twofold. First, we present a novel method of partitioning the bioinformatics data using consensus fuzzy clustering, where the recently proposed fuzzy clustering techniques are exploited. Second, we prepare three high quality subsets of all available indices. Superiority of the consensus fuzzy clustering method is demonstrated quantitatively, visually and statistically by comparing it with the previously proposed hierarchical clustered results. The processed AAindex1 database, supplementary material and the software are available at http://sysbio.icm.edu.pl/aaindex/ .

Introduces an approach to teaching aminoacids that employs the use of a poem containing information on the structure and properties of aminoacids, and of slides illustrating the poem. Student response to the method was positive. (MA)

The invention provides orthogonal translation systems for the production of polypeptides comprising unnatural aminoacids in methylotrophic yeast such as Pichia pastoris. Methods for producing polypeptides comprising unnatural aminoacids in methylotrophic yeast such as Pichia pastoris are also provided.

The invention provides orthogonal translation systems for the production of polypeptides comprising unnatural aminoacids in methyltrophic yeast such as Pichia pastoris. Methods for producing polypeptides comprising unnatural aminoacids in methyltrophic yeast such as Pichia pastoris are also provided.

A series of novel N-[(α)-(isoflavone-7-O-)acetyl] aminoacid methyl esters were prepared from the efficient and regioselective alkylation of isoflavones with chloroacetyl aminoacid derivatives under mild condition.

The aim of the study was to explore if changes in muscle and plasma aminoacid concentrations developed during growth and differed from levels seen in adults. The gradient and concentrations of free aminoacids in muscle and plasma were investigated in relation to age in metabolic healthy children. Plasma and specimens from the abdominal muscle were obtained during elective surgery. The children were grouped into three groups (group 1: aminoacids analysed increased with age, namely taurine, aspartate, threonine, alanine, valine, isoleucine, leucine, histidine, as well as the total sums of branched chain aminoacids (BCAA), basic aminoacids (BAA) and total sum of aminoacids (P aminoacids correlated with age (P < 0.05). These results indicate that there is an age dependency of the aminoacid pattern in skeletal muscle and plasma during growth.

Full Text Available BACKGROUND Decreased cellular thiol levels seen in diabetes mellitus (DM may be in part attributed to increased free radical generation. The free radical mediated oxidative stress has been implicated in the pathogenesis of DM and its complications. The relative deficiency or non-availability of insulin in DM affects the metabolism of biomolecules, specifically the carbohydrate metabolism. The insulin-mimicking actions of various thiols have been studied. In our previous study, we have documented that 3-mercapto- 1-propanol (Thiopropanol, a low molecular weight thiol, at the dosage employed has increased glucose utilisation in alloxandiabetic rat liver tissue probably by favouring utilisation of glucose through glycolysis and HMP pathway. It is known that insulin inhibits gluconeogenesis by inhibiting the key enzymes of the same and by controlling the channelling of aminoacids for the glucose biosynthesis through gluconeogenic pathway. A study was undertaken to assess the effects of thiopropanol (TP on aminoacid turnover and the redox status in alloxan diabetic rat liver. METHODS Male albino rats weighing 150-250 g were used. Diabetes was induced using alloxan monohydrate. Rats were divided into normal and diabetic groups. Levels of aminoacid nitrogen (AAN, alanine, total thiol (-SH groups, TBARS (Thiobarbituric acid reactive substances, and activities of alanine transaminase (ALT and aspartate transaminase (AST were estimated in liver specimens of normal, control-alloxan diabetic and TP-exposed-alloxan-diabetic rats. RESULTS The results showed a significant increase (p<0.001 in AAN levels, alanine levels, and total -SH groups concentration; and a significant decrease (p<0.001 in TBARS levels, ALT and AST activities in TP-exposed-alloxan diabetic liver slices as compared to control-alloxan diabetic liver slices. CONCLUSIONS Hence, it may be concluded that TP, at the concentration employed, inhibits gluconeogenesis from aminoacids probably by

When mollusc shells are analysed conventionally for aminoacid geochronology, the entire population of aminoacids is included, both inter- and intra-crystalline. This study investigates the utility of removing the aminoacids that are most susceptible to environmental effects by isolating the fraction of aminoacids encapsulated within mineral crystals of mollusc shells (intra-crystalline fraction). Bleaching, heating and leaching (diffusive loss) experiments were undertaken on modern and fo...

Hepatic encephalopathy may be caused by a decreased plasma ratio of branched-chain aminoacids (BCAA) to aromatic aminoacids. Treatment with BCAA may therefore have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be caused by a decreased plasma ratio of branched-chain aminoacids (BCAA) to aromatic aminoacids. Treatment with BCAA may therefore have a beneficial effect on patients with hepatic encephalopathy....

@@ β-Hydroxy-a-aminoacids are an important class of aminoacids due to their inherent biological investigations[1] and as structural components of more complex biomolecules.[2] β-Hydroxy-a-aminoacids have been used as intermediates in the asymmetric synthesis of other compounds.[3] An efficient and convenient concise method for the preparation of optically pure enantiomers of β-hydroxy-α-aminoacids would be of general interest.

Provided are methods of making carrier polypeptide that include incorporating a first unnatural aminoacid into a carrier polypeptide variant, incorporating a second unnatural aminoacid into a target polypeptide variant, and reacting the first and second unnatural aminoacids to produce the conjugate. Conjugates produced using the provided methods are also provided. In addition, orthogonal translation systems in methylotrophic yeast and methods of using these systems to produce carrier and target polypeptide variants comprising unnatural aminoacids are provided.

Provided are methods of making carrier polypeptide that include incorporating a first unnatural aminoacid into a carrier polypeptide variant, incorporating a second unnatural aminoacid into a target polypeptide variant, and reacting the first and second unnatural aminoacids to produce the conjugate. Conjugates produced using the provided methods are also provided. In addition, orthogonal translation systems in methylotrophic yeast and methods of using these systems to produce carrier and target polypeptide variants comprising unnatural aminoacids are provided.

Provided are methods of making carrier polypeptide that include incorporating a first unnatural aminoacid into a carrier polypeptide variant, incorporating a second unnatural aminoacid into a target polypeptide variant, and reacting the first and second unnatural aminoacids to produce the conjugate. Conjugates produced using the provided methods are also provided. In addition, orthogonal translation systems in methylotrophic yeast and methods of using these systems to produce carrier and target polypeptide variants comprising unnatural aminoacids are provided.

The stereoselective synthesis of aminoacids is of great importance for the construction of optically active natural products and pharmaceuticals. Apart from enzymes, a broad repertoire of chiral reagents, auxiliaries, and catalysts can be used for the formation of aminoacids. Asymmetric reactions using catalytic amounts of chiral molecules provide efficient methods for the generation of optically active proteinogenic and nonproteinogenic aminoacids. This minireview collects recent work on catalytic asymmetric synthesis of alpha- and beta-aminoacids.

Full Text Available Abstract Background Some aminoacid residues functionally interact with each other. This interaction will result in an evolutionary co-variation between these residues – coevolution. Our goal is to find these coevolving residues. Results We present six new methods for detecting coevolving residues. Among other things, we suggest measures that are variants of Mutual Information, and measures that use a multidimensional representation of each residue in order to capture the physico-chemical similarities between aminoacids. We created a benchmarking system, in silico, able to evaluate these methods through a wide range of realistic conditions. Finally, we use the combination of different methods as a way of improving performance. Conclusion Our best method (Row and Column Weighed Mutual Information has an estimated accuracy increase of 63% over Mutual Information. Furthermore, we show that the combination of different methods is efficient, and that the methods are quite sensitive to the different conditions tested.

The isotopic composition of hydrogen, nitrogen, and carbon in aminoacid and monocarboxylic acid extracts from the Murchison meteorite has been determined. The unusually high D/H and N-15/N-14 ratios in the aminoacid fraction are uniquely characteristic of known interstellar organic materials. The delta D value of the monocarboxylic acid fraction is lower but still consistent with an interstellar origin. These results confirm the extraterrestrial origin of both classes of compound and provide the first evidence suggesting a direct relationship between the massive organosynthesis occurring in interstellar clouds and the presence of prebiotic compounds in primitive planetary bodies.

Aminoacid chloramines (AACLs) are reactive secondary products of activated neutrophils. To understand AACL damage in cell nuclei, we exploited proliferating cell nuclear antigen (PCNA) as a nuclear protein damage reporter, using western blotting and mass spectrometry. Chloramines of proline, arginine, and glycine caused significant damage to PCNA in cells. Chloramines of taurine and histidine caused slight damage to PCNA in cells. Other AACLs caused no PCNA damage in intact cells. Evidence supports a sulfonamide, sulfinamide, or sulfenamide crosslinking mechanism involving cysteine 148 at the PCNA subunit interface, methionine sulfoxide formation as the basis of electrophoretic mobility shifting, and tyrosine and/or methionine residues as the likely targets of AACL damage to the PCNA antibody epitope. An interstitial fluid model experiment showed that physiological aminoacids can mediate HOCl damage to PCNA in the presence of proteins that would otherwise completely quench the HOCl. PCNA is a sensitive biomarker of AACL damage in cell nuclei. Arginine chloramine and proline chloramine, or reactive species derived from them, were shown to enter cells and damage PCNA. Aminoacids were shown to have at least two different mechanisms for suppressing PCNA damage in cells by their corresponding AACLs. Cysteine 148 was shown to be essential for PCNA subunit crosslinking by AACLs, and a crosslinking mechanism was proposed.